Serological estimation of the level of cross-fertilization in the monoecious liverwort Pellia epiphylla n = 9

Using protein antigens as markers, antigenic differentiation of progenies obtained from individual sporangia was examined. The experiments were expected to permit estimation of cross-fertilization frequency in the monoecious liverwort species, <em>Pellia epiphylla</em>, n = 9. The results obtained indicated segregation into two serological types, i.e. pointed to cross-fertilization, in approximately, 80% progenies. In correlation with electrophoretic studies, employing two peroxidase alleles and two shikimic acid dehydrogenase alleles as markers, the result made possible the establishment of cross-fertilization frequency at approximately 93% The data may indicate an absence of self-fertilization in this liverwort species and, thus, self-incompatibility. This may be included among the facors responsible for maintenance of genetic variability in populations of this species, in which haplophase is the prevalent phase of its life-cycle.

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Cross-fertilization as a reproductive strategy in a tissue flukesDidymosulcus katsuwonicola(Platyhelmintes: Didymozoidae) inferred by genetic analysis

Parasitology ◽

10.1017/s0031182015000839 ◽

2015 ◽

Vol 142 (11) ◽

pp. 1422-1429

Author(s):

IVONA MLADINEO ◽

MARINA TOMAŠ ◽

RINO STANIĆ

Keyword(s):

Life Cycle ◽

Haplotype Diversity ◽

Common Mechanism ◽

High Haplotype Diversity ◽

Atlantic Bluefin Tuna ◽

Food Borne ◽

Self Fertilization ◽

Successful Fulfillment ◽

Cross Fertilization ◽

Host Tissues

SUMMARYMitochondrial DNA locus cytochrome oxidase I was used to asses intraspecific genetic diversity of a didymozoid speciesDidymosulcus katsuwonicola.Adult forms of this species live encapsulated in pairs in the gills of the reared Atlantic bluefin tuna (Thunnus thynnus). The life cycle of this food-borne parasites and its migration in the host tissues after releasing from the digestive tract to the definitive site in the gills are unknown. Our goal was to assess whether two encysted didymozoids share the same haplotype, indicative of a common maternal origin, as well as the extent of cross- in respect to self-fertilization strategy. Intraspecific comparison showed high haplotype diversity, while the presence of two matching haplotypes within a single cyst encompassed only 17% of sampled individuals. This infers that cross-fertilization between paired individuals within the cyst is more common mechanism than self-fertilization. Such hermaphroditic parasite's trait suggests the existence of intricate infection and reproduction mechanisms, presumably as an adaptation for successful fulfillment of their indirect life cycle through dissemination of genetically more diverse and consequently more fit offspring.

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Pollination, Mating, and Reproduction in Plants

Pollination and Floral Ecology ◽

10.23943/princeton/9780691128610.003.0003 ◽

2011 ◽

Author(s):

Pat Willmer

Keyword(s):

Life Cycle ◽

Sexual Reproduction ◽

Male Gamete ◽

Plant Reproduction ◽

Pollen Grain ◽

Evolutionary Change ◽

Self Fertilization ◽

Plant Mating Systems ◽

Cross Fertilization ◽

Plant Sex

This chapter examines pollination, mating, and reproduction in plants. Plant reproduction can be either sexual or asexual, but the generation of new variants (which is the underlying necessity for adaptation to new or changing conditions and for evolutionary change) requires that at some point in the life cycle sexual reproduction occurs. In the case of angiosperms, the pollen grain is the male gamete, the equivalent of a spore in simpler plants. The ovule (egg) contains the female gamete. The chapter first provides an overview of plant fertilization before discussing plant sex and plant mating systems. It then considers the benefits of cross-fertilization and self-fertilization in plants, along with methods for avoiding selfing within a flower. It also describes methods for avoiding selfing between flowers within a plant and concludes with an analysis of methods for ensuring selfing.

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THE SIGNIFICANCE OF CROSS-FERTILIZATION AND SELF-FERTILIZATION FOR PRESERVING POPULATIONS’ STABILITY OF DOMINANT (LYMNAEA STAGNALIS) AND RARE (STAGNICOLA CORVUS) SPECIES OF FRESHWATER PULMONARY MOLLUSKS

Сибирский экологический журнал ◽

10.15372/sej20190508 ◽

2019 ◽

Keyword(s):

Lymnaea Stagnalis ◽

Self Fertilization ◽

Cross Fertilization

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Sequence and Structural Diversity of the S Locus Genes From Different Lines With the Same Self-Recognition Specificities in Brassica oleracea

Genetics ◽

10.1093/genetics/154.1.413 ◽

2000 ◽

Vol 154 (1) ◽

pp. 413-420 ◽

Cited By ~ 2

Author(s):

Makoto Kusaba ◽

Masanori Matsushita ◽

Keiichi Okazaki ◽

Yoko Satta ◽

Takeshi Nishio

Keyword(s):

Structural Diversity ◽

Receptor Protein ◽

Self Incompatibility ◽

S Locus ◽

High Similarity ◽

Putative Receptor ◽

Recognition Specificity ◽

Polymorphic Genes ◽

Self Recognition ◽

Self Fertilization

Abstract Self-incompatibility (SI) is a mechanism for preventing self-fertilization in flowering plants. In Brassica, it is controlled by a single multi-allelic locus, S, and it is believed that two highly polymorphic genes in the S locus, SLG and SRK, play central roles in self-recognition in stigmas. SRK is a putative receptor protein kinase, whose extracellular domain exhibits high similarity to SLG. We analyzed two pairs of lines showing cross-incompatibility (S2 and S2-b; S13 and S13-b). In S2 and S2-b, SRKs were more highly conserved than SLGs. This was also the case with S13 and S13-b. This suggests that the SRKs of different lines must be conserved for the lines to have the same self-recognition specificity. In particular, SLG2-b showed only 88.5% identity to SLG2, which is comparable to that between the SLGs of different S haplotypes, while SRK2-b showed 97.3% identity to SRK2 in the S domain. These findings suggest that the SLGs in these S haplotypes are not important for self-recognition in SI.

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Transcriptome and Network Analyses of Heterostyly in Turnera subulata Provide Mechanistic Insights: Are S-Loci a Red-Light for Pistil Elongation?

Plants ◽

10.3390/plants9060713 ◽

2020 ◽

Vol 9 (6) ◽

pp. 713 ◽

Cited By ~ 1

Author(s):

Paige M. Henning ◽

Joel S. Shore ◽

Andrew G. McCubbin

Keyword(s):

Red Light ◽

Genetic Networks ◽

Light Signaling ◽

Self Incompatibility ◽

S Locus ◽

Network Analyses ◽

S Gene ◽

Self Fertilization ◽

Pistil Length ◽

S Genes

Heterostyly employs distinct hermaphroditic floral morphs to enforce outbreeding. Morphs differ structurally in stigma/anther positioning, promoting cross-pollination, and physiologically blocking self-fertilization. Heterostyly is controlled by a self-incompatibility (S)-locus of a small number of linked S-genes specific to short-styled morph genomes. Turnera possesses three S-genes, namely TsBAHD (controlling pistil characters), TsYUC6, and TsSPH1 (controlling stamen characters). Here, we compare pistil and stamen transcriptomes of floral morphs of T. subulata to investigate hypothesized S-gene function(s) and whether hormonal differences might contribute to physiological incompatibility. We then use network analyses to identify genetic networks underpinning heterostyly. We found a depletion of brassinosteroid-regulated genes in short styled (S)-morph pistils, consistent with hypothesized brassinosteroid-inactivating activity of TsBAHD. In S-morph anthers, auxin-regulated genes were enriched, consistent with hypothesized auxin biosynthesis activity of TsYUC6. Evidence was found for auxin elevation and brassinosteroid reduction in both pistils and stamens of S- relative to long styled (L)-morph flowers, consistent with reciprocal hormonal differences contributing to physiological incompatibility. Additional hormone pathways were also affected, however, suggesting S-gene activities intersect with a signaling hub. Interestingly, distinct S-genes controlling pistil length, from three species with independently evolved heterostyly, potentially intersect with phytochrome interacting factor (PIF) network hubs which mediate red/far-red light signaling. We propose that modification of the activities of PIF hubs by the S-locus could be a common theme in the evolution of heterostyly.

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The Turnera Style S-Locus Gene TsBAHD Possesses Brassinosteroid-Inactivating Activity When Expressed in Arabidopsis thaliana

Plants ◽

10.3390/plants9111566 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1566

Author(s):

Courtney M. Matzke ◽

Joel S. Shore ◽

Michael M. Neff ◽

Andrew G. McCubbin

Keyword(s):

Arabidopsis Thaliana ◽

Empirical Support ◽

Self Incompatibility ◽

S Locus ◽

Style Length ◽

Hypocotyl Growth ◽

Genes Encoding ◽

Endogenous Genes ◽

Self Fertilization ◽

Floral Form

Heterostyly distinct hermaphroditic floral morphs enforce outbreeding. Morphs differ structurally, promote cross-pollination, and physiologically block self-fertilization. In Turnera the self-incompatibility (S)-locus controlling heterostyly possesses three genes specific to short-styled morph genomes. Only one gene, TsBAHD, is expressed in pistils and this has been hypothesized to possess brassinosteroid (BR)-inactivating activity. We tested this hypothesis using heterologous expression in Arabidopsis thaliana as a bioassay, thereby assessing growth phenotype, and the impacts on the expression of endogenous genes involved in BR homeostasis and seedling photomorphogenesis. Transgenic A. thaliana expressing TsBAHD displayed phenotypes typical of BR-deficient mutants, with phenotype severity dependent on TsBAHD expression level. BAS1, which encodes an enzyme involved in BR inactivation, was downregulated in TsBAHD-expressing lines. CPD and DWF, which encode enzymes involved in BR biosynthesis, were upregulated. Hypocotyl growth of TsBAHD dwarfs responded to application of brassinolide in light and dark in a manner typical of plants over-expressing genes encoding BR-inactivating activity. These results provide empirical support for the hypothesis that TsBAHD possesses BR-inactivating activity. Further this suggests that style length in Turnera is controlled by the same mechanism (BR inactivation) as that reported for Primula, but using a different class of enzyme. This reveals interesting convergent evolution in a biochemical mechanism to regulate floral form in heterostyly.

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Flower drop and fruit set in field beans, Vicia faba L.

The Journal of Agricultural Science ◽

10.1017/s0021859600020499 ◽

1969 ◽

Vol 72 (1) ◽

pp. 131-138 ◽

Cited By ~ 38

Author(s):

A. E. Kambal

Keyword(s):

Vicia Faba ◽

Fruit Set ◽

Local Strain ◽

Insect Pollination ◽

Pod Yield ◽

Vicia Faba L ◽

Before And After ◽

Self Fertilization ◽

Cross Fertilization ◽

Field Beans

SUMMARYThe percentage of the total buds produced that dropped before reaching the mature pod stage was estimated as 86·7% in Baladi, a local strain of field beans, and 93·7% in Giza 1, a variety introduced from Egypt. The drop was appreciable both before and after fertilization. There were indications that both inadequate insect pollination and inter-ovary competition contributed to the reduction of pod yield.Self pollen was detected on the stigma in the bud stage 2–3 days before the flower was open. Estimates of natural cross-fertilization ranged from 35·8 to 42·1%, indicating that self-pollination did not lead to complete self fertilization. Hand manipulation of the flowers increased pod set in most of the cases but the line 1W did not respond to this treatment and proved to be highly autofertile.

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Self-incompatibility in Papaver: identification of the pollen S-determinant PrpS

Biochemical Society Transactions ◽

10.1042/bst0380588 ◽

2010 ◽

Vol 38 (2) ◽

pp. 588-592 ◽

Cited By ~ 10

Author(s):

Natalie S. Poulter ◽

Michael J. Wheeler ◽

Maurice Bosch ◽

Vernonica E. Franklin-Tong

Keyword(s):

Transmembrane Protein ◽

Mitogen Activated Protein Kinase ◽

Self Incompatibility ◽

Incompatible Pollen ◽

Signalling Network ◽

Mitogen Activated Protein ◽

Significant Step ◽

Self Fertilization ◽

Subsequent Loss

Many flowering plants are hermaphrodite, posing the problem of self-fertilization and the subsequent loss of the genetic fitness of the offspring. To prevent this, many plants have developed a genetically controlled mechanism called self-incompatibility (SI). When the male and female S-determinants match, self (incompatible) pollen is recognized and rejected before fertilization can occur. In poppy (Papaver rhoeas), the pistil S-determinant (PrsS) is a small secreted protein that interacts with incompatible pollen, initiating a Ca2+-dependent signalling network. SI triggers several downstream events, including depolymerization of the cytoskeleton, phosphorylation of two soluble inorganic pyrophosphatases and an MAPK (mitogen-activated protein kinase). This culminates in PCD (programmed cell death) involving several caspase-like activities. The recent discovery of the Papaver pollen S-determinant PrpS marks a significant step forward in the understanding of the Papaver SI system. PrpS encodes a ~20 kDa predicted transmembrane protein which has no homology with known proteins. It is specifically expressed in pollen, linked to the pistil S-determinant, and displays the high polymorphism expected of an S-locus determinant. The present review focuses on the discovery and characterization of PrpS which strongly support the hypothesis that Papaver SI is triggered by the interaction of PrsS and PrpS.

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