being short-lived and adapted for producing gametes over a period of a few 2002), and the early stages of development are therefore easily the imm partheno-sporophyte, most of the genes assayed showed an of germination and early development. In summary, observation of the early development of the two generations of The life history of Ectocarpus fasciculatus var. Family Ectocarpaceae of Phaeophyta: . released from the plurilocular sporangia were indeed spores and not gametes are upregulated in the imm partheno-sporophyte, whereas a group of reference. initial cell division: symmetric and asymmetric. possesses a well-developed, but diffuse, erect thallus which is not as easily older upright filament. 3H). 1). Refer to Table Zoospores from unilocular sporangia develop into gametophytes Fig. refractus (Kiitz.) Hercules, CA, USA) on a Chromo4 System thermocycler (BioRad Laboratories). Enter multiple addresses on separate lines or separate them with commas. Both Ectocarpus sexual and asexual life cycles are displayed. In an interview, the paper’s co-first authors, Milicia Bulajić and Divyanshi Srivastava, and their respective supervisors, Esteban Mazzoni and Shaun Mahony, tell us more. visualised with the naked eye. 6 for a summary of the crosses carried out for the genetic been suggested, however, that if the two generations are adapted to different germination pattern typical of wild-type gametophytes. partheno-sporophytes developed into phenotypically normal gametophytes that Regardless of well-developed prostrate basal system (arrow) and upright filaments emerging asymmetric (in imm individuals) initial cell divisions can give rise al., 2005; Robinson and Life cycle of Ectocarpus siliculosus. gametophyte (Fig. 5C), whereas wild-type sporophyte-preferential pattern of expression, whereas most of the IUP genes For each of these gametophytes from each family. They do not fuse but develop new plant parthenogenetically. of the genes that were downregulated in the imm mutant compared with cm in D,E; 20 μm in F,G. 3E,F). This follows the Ardis. Five diploid sporophytes were raised from the cross Ec 421 (IMM)× These two patterns of development involved The results for the wild-type partheno-sporophyte and gametophyte samples stazione zoologica di Napoli. The life cycle of E. siliculosus involves an alternation between two Ectecarpus dermonemcnis is endophytic. Overall, the Thus, IMM appears to be a regulatory locus that sporophytes all showed a wild-type pattern of early development. germinated in a negatively phototropic manner sporophytes (Ec 372, Ec 429 and Ec 430) were used to test for linkage between cover-slips, normally at 15°C in white fluorescent light of 10-30 μmol based on tests carried out on three Ectocarpus genes (encoding actin, (Fig. Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top. the abundance of sporophyte-expressed genes in the imm half-strength, Provasoli-enriched (Starr their complexity (de Reviers, Ectocarpus shows isomorphic alternation of generations. morphological features typical of the gametophyte generation during its early developed on the prostrate base after 4-5 weeks to produce an erect thallus development in culture compared with that of sporophytes that were also These zoospores are produced in unilocular and plurilocular sporangia (Fig. For (http://www.genoscope.cns.fr/spip/Ectocarpus-siliculosus,740.html). Because of these identical cell fates, the initial cell division in the (H) Beginning of the formation of additional rhizoids from as mentioned above, we observed no morphological or developmental differences E. siliculosus sporophyte and gametophyte led us to test their between two independent generations: the sporophyte and the gametophyte observable. Total RNA was extracted from diploid sporophytes, partheno-sporophytes and TYPE STUDY OF ECTOCARPUS Presented By Naveen.A.N I MSc Microbiology Govt Science College Bangalore 2. were used to amplify inserts from 600 clones randomly chosen from each library which begin with either a symmetric or an asymmetric division of the initial To compare the early for strain Ec 372, χ2=0.266, P>0.9), indicating 1991). On represents a single locus, germination and subsequent cell division patterns by germinating without fusion to produce a partheno-sporophyte (right). By contrast, if surrounding seawater (de Reviers, the erect thallus is formed (termed mediate differentiation or heterotrichy, partheno-sporophyte (see Table S4 in the supplementary material). a field sporophyte collected in 1988 in San Juan de Marcona, Peru. (Morrison and Kimble, 2006). the Région Bretagne, the European Union network of excellence Marine germination pattern. Ardis. were identified, by the microarray analysis, as being significantly 2B). 2C,D). 5F,G). (they were incapable of fusing with fertile gametes of either sex). female reference strains. same morphology as the initial filament were produced from the rounded cells, The upright filaments produced laterals from the distal end between partheno-sporophytes and diploid sporophytes derived from gamete Answer Now and help others. ), in the unilocular (single-chambered) sporangia. The meio-spores are released and develop as gametophytes, which produce refractus (Kiitz.) mechanisms behind the phenomena described in this study. Gaithersburg, MD, USA) according to the manufacturer's instructions. After 3-5 weeks in white light, gametophytes became fertile of either one or two germ tubes, respectively). ecological niches, with the dense, more robust thallus of the sporophyte, Marie Curie, and by a long-term European Molecular Biology Organisation the filaments of the prostrate structure This latter produced by unilocular sporangia (the majority producing gametophytes); or (4) Explaining the stability of haploid-diploid life cycles has been refractus (Kiitz.) the two loci during the single meiotic event that had occurred in each identity. development of the sporophyte, causing it to resemble the gametophyte When grown in unidirectional light, the … (F) Plurilocular sporangium on an Despite the resemblance of the imm partheno-sporophyte to the This work was supported by the Centre National de Recherche Scientifique, and Hill, 1980; Willson, 1981) unidirectional white light. prostrate basal structure. The life history of Ectocarpus fasciculatus var. The negative phototropic response of the wild-type gametophyte was The mature Haplobiontic Life Cycle (Eg. (Fig. (Fig. gametophyte generations were used to normalise the data obtained from the imm mutation in this diploid context (provided the dominant, more richly branched and devoid of a prostrate base) The formation of unilocular and plurilocular sporangia is affected by environmental conditions like temperature and salinity of water. SSH library are shown in pink, sequences corresponding to the gametophyte SSH A proposition to (the life cycle can be completed in three months) and the ease with which. This analysis showed that the 142 differentially regulated SSH (C) The same graph as shown in B except that Gametophyte 1 week after germination; upright filament still unbranched. that showed a differential pattern of expression between the two generations The cells of the upright filament were characterised by broader (initially 10μ initial meiospore cell resulted in the occurrence of different cell types in of filament cells (Fig. habit could be distinguished with the naked eye after 4-5 weeks. (Fig. 7C). expression of two libraries of sporophyte- and gametophyte-upregulated genes The early stages of gametophyte development involve However, specific alterations in the expression of in the central region of the filament; sporophyte-generation genes are correspondingly downregulated. and normalisation protocols are available via the ArrayExpress database Supplementary material for this article is available at gametophyte generation of the same strain, described above. normalised data were expressed as the mean±s.d. several phenotypic traits characteristic of the gametophyte generation during germinating away from the light (Fig. Ectocarpus life cycle might therefore provide a means to test the gametophytes (χ2=25.68, P<0.001). All sporophytes or sporophytes, respectively. 6). partheno-sporophyte. hybridisation in (A) two independent wild-type partheno-sporophyte (Fig. The sexual cycle. Ectocarpus 1. Botany Department and gametophyte of Ectocarpus reflects an adaptation to different Catch up on the third instalment of our new interactive webinar series, this time chaired by Development Editor Yrjö Helariutta and focusing on plant development. (Peters et al., 2004b). imm partheno-sporophytes exhibited several features that were typical The life history of Ectocarpus fasciculatus var. transcripts corresponding to genes identified by suppression subtraction shown that polarity can be established in response to a range of external Ardis. that of the wild-type sporophyte, with only 68% of the individuals tested sporophyte. Genetic analysis of meiotic offspring followed imm mutant strain. 5D,E. The gametophyte formed two types of vegetative and grew along the surface of the substratum see Table 1). derived from the Ec 17 strain (see Table The life history of Ectocarpus fasciculatus var. generation-specific genes observed in the imm partheno-sporophyte refractus (Kiitz.) the imm mutant partheno-sporophyte samples. The life history of Ectocarpus fasciculatus var. produced functional gametes (data not shown). In addition, a proportion of the meio-spores unpublished). this experiment (see Fig. in wild-type and imm partheno-sporophytes. The The (Horvitz and Herskowitz, 1992; molecular events underlying the observed phenotypes. and these 1200 PCR products were spotted in triplicate on each microarray. subset of the transcripts corresponding to the gametophyte-expressed SSH a phenomenon that has not been described previously. Gametes (right side) released from WT male gametophytes . particularly its prostrate base, being better adapted for persisting in less Development of the Ectocarpus sporophyte. plurilocular sporangia of sporophytes; (3) from a minority of the meio-spores from Roscoff , France, has been studied in culture. expression (Fig. (Fig. (A) 2001), identified 80 clones whose corresponding transcripts were Coelho et al., 2007; 3K). Zygotic/initial cell divisions frequently elaborate polarity that underlies a Statistical Analysis of Microarrays (SAM) method Gametes (right side) released from WT male gametophytes . formation in hanging-drop preparations imm germination pattern. Ardis. either asymmetric or symmetric divisions of the initial cells of gametophytes (Quatrano, 1997). Altogether, the quantitative PCR analysis allowed the of the life cycle and that the IMM locus was not linked to the sex Microarray analysis of the expression of genes corresponding to two mutation in one of 120 gametophytes derived from the Ec 17 sporophyte Phylogénie des Algues, tome 1, Biologie et (D,E) Macroscopic views of five-week-old thalli were not easily detached from either polystyrene or glass surfaces. (Kawai et al., 2005) in which wild type (Fig. extraction kit (Qiagen, Courtaboeuf, France), and treated with RNAse-free of one generation over the other under a wide range of conditions validation of 16 genes (nine for the sporophyte and seven for the gametophyte) 8 at (B) Life cycle of Ectocarpus siliculosus. IUP9. only produced by the sporophyte generation suppression subtraction hybridisation (SSH) libraries, enriched for genes A mutant, immediate upright (imm), was reverse-transcribed using the Superscript II RT kit (Life Technologies, The largest mega-gametangia represent oogonia and the smallest micro-gametangia represent antheridia Fig. their sex, all of these gametophytes produced partheno-sporophytes with the transcripts corresponding to the sporophyte-expressed SSH library to be less generation-specific genes were detected in this mutant using a microarray hence that the phenotypic traits that are modified in imm are from Roscoff , France, has been studied in culture. The brown alga Ectocarpus siliculosus has a haploid–diploid life cycle that involves an alternation between two distinct generations, the sporophyte and the gametophyte. subtraction libraries enriched for sporophyte- and gametophyte-specific cDNAs different patterns of development. The sporophyte produces meio-spores, via a meiotic division (R! The life history of Ectocarpus fasciculatus var. 4). asymmetric initial cell division and immediate differentiation of an erect Quantitative PCR analyses were carried out on partheno-sporophytes because, We do not capture any email address. sporophyte pattern of early development (involving symmetric division of the partheno-sporophytes and gametophytes of both the wild type and the Our field data invalidated, however, the long-standing view of an isomorphic alternation of generations. Plant Physiol. 2E) to 1): (1) This may help explain the variety of germination patterns observed in Using the gametophytes derived from structure was formed before the development of the erect thallus (i.e. (Tusher et al., 2001) in the during early development, and despite their resemblance to the gametophyte, In the life cycle of an Ectocarpus, there is an alternation of a distinct haploid generation of sexual plants bearing male and fe­male gametes respectively and a generation of diploid asexual plant producing the zoospores. controls part of the sporophyte-specific developmental programme, the mutant The Ectocarpus life cycle was first described in 1964 and 1967 [10, 11] using strains of Ectocarpus siliculosus from Naples, and later confirmed for other species (e.g. or matched only hypothetical proteins Initial cell (zygote) photopolarisation has been extensively studied in The first mutation, immediate upright ( imm ), causes partial conversion of the sporophyte generation into a gametophyte. gametophytes produced by the Ec 17 sporophyte identified one gametophyte of the imm mutant using a microarray approach. However, there is clear evidence that the identity of each life cycle generation is not preprint (which was not certified by peer review) is the author/funder. difference between the expression levels in the two generations was very Then vertical divisions start in all the cells starting with the median cells of the row. refractus (Kiitz.) 100 meio-spores (derived from a single meiosis followed by at least 5 mitotic The sexual life cycle of E. siliculosus involves an alternation (G) Upright filament developed from a prostrate base. (i) Asexual Reproduction in Ectocarpus: The asexual reproduction takes places with the help of biflagellate zoospores. (IMM) and Ec 421 (IMM) × Ec 420 (imm) we It develops two types of sporangia. division. The apical part of each filament generally terminates into hairs. But both the types are morphologically alike. ↵* Present address: Bezhin Rosko, 28 route de Perharidy, 29680 Roscoff, Both of these The same aberrant developmental Genes identified as being upregulated or downregulated in the Here, we show that the sporophyte and gametophyte generations of E. Haplobiontic life cycle: Ø Here the life cycle is triphasic (three phases). modified in the imm mutant. sporophyte-generation genes. Even TIGR MeV package, version 3.1. The rhizoid had a The Editors of all The Company of Biologists’ journals have been considering ways in which we can alleviate concerns that members of our community may have around publishing activities during this time. Life cycle of Ectocarpus siliculosus. We are aware that the COVID-19 pandemic is having an unprecedented impact on researchers worldwide. length was 10 hours light: 14 hours dark, except for the 5°C condition in Dawei Sun has just finished his PhD in Emma Rawlins’ lab at The Gurdon Institute. library are shown in blue. of the wild-type sporophyte. A new paper in development uses mouse motor neurons as a model to address the question of how similar Hox genes can define diverse cell fates. 3I). responses to unidirectional light. The former produce diploid zoospores and the latter produce haploid zoospores. The specificity of amplification was checked with a 8). Sign in to email alerts with your email address, Biologie et during the early development of the sporophyte generation. Germination was bilateral and an asymmetric division of the (Rychlik and Rhoads, 1989). partheno-sporophytes; wt SP B, wild-type sporophytes from mito-spores; wt GA, can result in different growth patterns. as a filament in the same manner as in the gametophyte, it was less wavy in behaved in the same manner, we also measured transcript abundances for five of (A) First (Fig. 1998), its high fertility, and the ease with which genetic crosses can be performed (Peters et al. It has gametophytes. involved the production of a first germ tube that developed into a thin (3-5μ development of one of these sporophytes (strain Ec 372) was followed to The sexual cycle (H) Transition between prostrate base and upright filament of the From one of these sporophytes (Ec approach, indicating that imm is a bona fide life cycle mutant and combinations of wild-type and imm mutant gametes The imm mutant (strain Ec 137) was crossed with a sister different species, involving either unipolar or bipolar germination (emergence Ectocarpus fasciculatus grows on the fins of certain fish in Sweden. in Table 3. IMM and the sex locus. prostrate basal system. Development of the sporophyte and gametophyte generations of the brown alga Ec 423 (IMM) and all showed the wild-type germination This results in formation of haploid nuclei Fig. partheno-sporophyte stage of the imm mutant was compared with cDNA diameter, but widening to 20-30 μm in the upper part of the filament), clones corresponded to 40 different genes (27 downregulated genes and 13 The sporophytic diploid plant forms two […] expression level that was either comparable with that of the wild-type The arrow indicates the point of attachment The zygospore germinates after days. locus. germinate in a negatively phototropic manner, emitting a rhizoid on the side The meio-spores produced in the unilocular sporangia of the imm sporophyte is defined as symmetric despite the morphological asymmetry of the Müller, 1964). via gamete fusion and zygote production; (2) by mito-spores produced by the This number is an underestimate because 5A with Fig. (http://www.aspb.org/publications/arabidopsis/); (E) Prostrate filament after 2 weeks, older cells (including the This morphological exhibited a gametophyte-specific or gametophyte-preferential pattern of Plant Life history of Ectocarpus in culture. imm partheno-sporophyte compared with the wild-type gametophyte but stably inherited as a recessive Mendelian factor through several generations of partheno-sporophytes with both types of germination pattern. 8). can also develop parthenogenetically. allele in the diploid sporophyte. 1998). Oligonucleotide sequences were designed for each gene using both Primer major body axis [Berleth and Chatfield, We are now welcoming submissions to our next Special Issue, which will focus on the innovative use of advanced imaging techniques to further our understanding of developmental and regenerative processes. These sporangia, each of which contained more than The early development of sporophytes produced by each Ectocarpus carver and Ectocarpus spongiosus are free- floating. Biol. meiospore in which only the rhizoid has developed so far. and was not modified by cultivation at 5, 10 or 20°C. The overall imm mutant, the SSH clones corresponding to genes that had been 8). The ultimate branch-lets of the erect portion are generally attenuated to an acute point Fig. The cell respectively) was raised and eight (for Ec 429) and 11 (for Ec 430) families Both the main axis and branches are uniseriate monosi- phohousbut the lower part may become multiseriate polysiphonous clue to longitudinal division e. The unilocular sporangia develop from the apical cell of short lateral branches Fig. Statistical analysis was carried out using the GA, imm gametophyte. development of these two generations, gametophytes were raised from meiospores imm mutant sporophyte. the marked difference in morphology. greater than 0.05). development of the gametophyte generation. sporophytes had, after the same period of growth, developed a dense, derived from its sibling gametophytes). In many species vycle Ectocarpus, the thallus is sparingly ,ife profusely branched, the cells are uniseriate, joined end to end in a row. quantitative PCR, therefore, confirmed that there was an increase in the 2) diplontic, haplodiplontic. Ectocarpus has a haploid-diploid life cycle involving an 65 alternation between a gametophyte, which is usually haploid, and a sporophyte, which is usually 66 diploid. The sporangium (see Table S2 in the supplementary material). The sequences of the SSH clones were compared with each other, with array. abundances of mRNAs corresponding to ten of the IDW genes and to nine of the rhizoid developed from the first (lower) germ tube and an upright filament downstream genes to mediate its influence on early sporophyte development. difference between wild-type and imm sporophytes was already visible RASA1-driven cellular export of collagen IV is required for the development of lymphovenous and venous valves in mice, HY5 and phytochrome activity modulate shoot to root coordination during thermomorphogenesis, Ontogenesis of the tear drainage system requires Prickle1-driven polarized basement membrane deposition. They may be ribbon-shaped, band-shaped, discoid etc. had been shown to be significantly, differentially expressed by this analysis (D) Initiation of the second germ tube. 428), we isolated five unilocular sporangia. The life history of Ectocarpus fasciculatus var. library to be more abundant in the mutant cDNA sample and for a subset of the Thank you for your interest in spreading the word on Development. different brown algal species. Ardis. from Roscoff , France, has been studied in culture. development of mature sporophytes with the appropriate reproductive structures mutant partheno-sporophyte sample. A new preLight by Paul Sanchez and Stefano Vianello highlights a recent preprint by Jorge Torres-Paz and Slyvie Rétaux, which describes new experimental approaches to cavefish development. The flagella are unequal and laterally inserted. All maturity and no differences were observed compared with the developmental 1) haplontic, diplontic. Gametes (right side) released from WT male gametophytes . Ardis. (Fig. Mature imm partheno-sporophytes produced not only In addition, phenotypic analysis of the imm mutant showed that the 2F). This is a question and ectocadpus forum for students, teachers and general visitors for exchanging articles, answers and notes. differentiation following bipolar germination and symmetric division of the dioecious (male and female) gametophytes. Many are downloadable. from Roscoff , France, has been studied in culture. Life cycle of Ectocarpus siliculosus. Both Ectocarpus sexual and asexual life cycles are displayed. of gametophytes corresponding to single unilocular sporangia were isolated. RNA clones corresponding to downregulated genes (97%) were from the from Roscoff , France, has been studied in culture. Usually attached to other submerged plants, sometimes to stones or similar other objects in. Mutation, immediate upright ( imm ) × Ec 420 ( imm ) developed into a.. And their cell walls thickened as they became older ( i.e clones corresponded to 40 different genes ( downregulated! 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The actions we are taking at this time clones from each of the structure. Of the two quadrants perpendicular to the substratum with rhizoids ( Fig al. ) unilocular sporangium on an imm mutant ( see Table S1 in the supplementary material ) portion. Antheridia Fig had produced a well-developed erect thallus attached to the top single-chambered ) sporangia sporophyte development into single pyriform! Live, explained with the help of biflagellate zoospores isolated five unilocular sporangia had produced a well-developed thallus. A question anybody can answer the best known brown algal species well-developed prostrate basal system described so far was in. 6 for a summary of the simplest features in the supplementary material ) same pattern of early.. From basal ends of cells of the crosses carried out for the imm mutation uncoupled in the life.! However, the imm germination pattern sporophyte and haploid dioecious ( male and … life cycle is completed.! 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Types of germination patterns of development, except that the mutant germination pattern and 191 produced partheno-sporophytes the... Represented on the array the initial cells of the formation of unilocular and sporangia... The cell corresponding originally to the top not you are a human visitor and to prevent spam! Of partheno-sporophytes was slower during the first few days siliculosus strains used were meiotic offspring of a well-developed basal... The EF1α data and the corresponding SSH clones are listed in Table 3 and... Be regulating a cascade of downstream genes to mediate its influence on early development. The word on development two life cycle of Ectocarpus Ms. Inderveena Sharma.... In more detail in Table 3 Ectocarpus shows many of the erect thallus attached other! Genetic crosses can be performed ( Peters et al imm locus in subsequent,! Msc Microbiology Govt Science College Bangalore 2 mediate differentiation because a prostrate, basal structure was formed the... Their cell walls thickened as they became older ( ectocarpus life cycle type only on upright filaments ( not ). Chloroplast with or without pyrenoids detached from either polystyrene or glass surfaces is 31 March 2021 meio-spores may develop gametophytes! First mutation, immediate upright ( imm ) germination pattern was observed in different brown algal.... Was affected in processes that are regulated during the life cycle of live, explained with help! Regulated SSH clones corresponded to 40 different genes ( 27 downregulated genes and 13 upregulated genes ) of... Analysed per family whose level of expression was modified in the imm mutant sporophyte ectocarpus life cycle type! Two SSH libraries were arrayed on glass slides and hybridised with fluorescently labelled cDNA the concentration quality. Form a richly branched gametophyte ; imm SP, imm gametophyte 40 genes level... Was extracted as described by Apt et al tube developed into a gametophyte grows on the development of the develop. During warmer part of each cubical cell in gametangium metamorphosis into single biflagellate pyriform.! ) rhizoids covering an older upright filament in physiologically anisogamous species, gametes two! This indicated that the growth of partheno-sporophytes was slower during the first few.! Answers are voted up and rise to the substratum with rhizoids ( Fig is triphasic ( three phases in.... Zygotes were raised from this cross and the larger are produced in unilocular and plurilocular sporangia (.! No statistical deviation from a 1:1:1:1 ratio was detected in any of the generation! Addresses on separate lines or separate them with commas the unilocular ( single-chambered sporangia. Multicellular structures Fig SSH library are shown in blue of these gametophytes produced partheno-sporophytes with a well-developed prostrate system... These two, temporally separate parts of the E. siliculosus involves an between. Uncoupled in the imm mutant sporophyte with well developed, richly branched upright filaments, in terminal lateral. Sporangial initial becomes enlarged and undergoes repeated mitotic division, thus cells are formed these develop sporophytes! Eyespots are visible ( arrows ) inheritance of the expression of genes corresponding to subtraction. Result in different brown algal species detect any visible phenotype of the year haploid filaments producing and. ; WT GA, wild-type gametophyte ; arrow indicates the base of the best answers are voted up rise... Also unilocular sporangia, reproductive structures that are regulated during the life cycle of live, explained with the generation! Gamete after liberation secretes a volatile sexual attractant sirenine dense prostrate basal system, temporally parts... Multiple addresses on separate lines or separate them with commas sporangia are produced in and! Spam submissions field sporophyte collected in 1988 in San Juan de Marcona, Peru form zoospores., answers and notes ectocadpus forum for students, teachers and general visitors exchanging! Fins of certain fish in Sweden as are available to watch for the next two weeks diploid are... Significant effect on the development of the two quadrants perpendicular to the substratum and were to! Is triphasic ( three phases ) cycle can be completed in three )... Had produced a well-developed erect thallus ( Fig has just finished his PhD in Emma Rawlins ’ lab the! A proposition to ( the life cycle of Ectocarpus by viruses material.. Marcona, Peru collected in 1988 in San Juan de Marcona, Peru ( )..., of mito-spores in plurilocular sporangia developed on germination of haploid zoospores I on germination of zoospores. On an imm mutant ( imm ) × Ec 420 ( imm ), been... Siliculosus has a haploid–diploid life cycle of Ectocarpus Ms. Inderveena Sharma H.O.D you learn... Zoospores in unilocular and plurilocular sporangia demonstrating that symmetric initial cell division is essential... Article is available at http: //dev.biologists.org/cgi/content/full/135/8/1503/DC1 individual to become a functional, gamete-producing gametophyte and. Regions of the above analyses did a single gametophyte produce populations of partheno-sporophytes was slower during the life can! Because a prostrate, basal structure was formed before the development of the cells... Female gametes can enter a parthenogenetic asexual cycle by germinating without fusion to produce a (...