Unreduced gamete formation in wheat × Aegilops spp. hybrids is genotype specific and prevented by shared homologous subgenomes

2016 ◽  
Vol 35 (5) ◽  
pp. 1143-1154 ◽  
Author(s):  
Zhaleh Fakhri ◽  
Ghader Mirzaghaderi ◽  
Samira Ahmadian ◽  
Annaliese S. Mason
Keyword(s):  
Unreduced Gamete ◽  
Gamete Formation

scholarly journals Transcriptome Analysis of Young Ovaries Reveals Candidate Genes Involved in Gamete Formation in Lantana camara

Plants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 263 ◽  
Author(s):  
Ze Peng ◽  
Krishna Bhattarai ◽  
Saroj Parajuli ◽  
Zhe Cao ◽  
Zhanao Deng
Keyword(s):  
Candidate Genes ◽  
De Novo ◽  
Transcriptome Assembly ◽  
Gene Families ◽  
Unreduced Gametes ◽  
Lantana Camara ◽  
Unreduced Gamete ◽  
Genomic Resources ◽  
Gamete Formation ◽  
Gamete Production

Lantana (Lantana camara L., Verbenaceae) is an important ornamental crop, yet can be a highly invasive species. The formation of unreduced female gametes (UFGs) is a major factor contributing to its invasiveness and has severely hindered the development of sterile cultivars. To enrich the genomic resources and gain insight into the genetic mechanisms of UFG formation in lantana, we investigated the transcriptomes of young ovaries of two lantana genotypes, GDGHOP-36 (GGO), producing 100% UFGs, and a cultivar Landmark White Lantana (LWL), not producing UFGs. The de novo transcriptome assembly resulted in a total of 90,641 unique transcript sequences with an N50 of 1692 bp, among which, 29,383 sequences contained full-length coding sequences (CDS). There were 214 transcripts associated with the biological processes of gamete production and 10 gene families orthologous to genes known to control unreduced gamete production in Arabidopsis. We identified 925 transcription factor (TF)-encoding sequences, 91 nucleotide-binding site (NBS)-containing genes, and gene families related to drought/salt tolerance and allelopathy. These genomic resources and candidate genes involved in gamete formation will be valuable for developing new tools to control the invasiveness in L. camara, protect native lantana species, and understand the formation of unreduced gametes in plants.

scholarly journals Asynapsis and unreduced gamete formation in a Trifolium interspecific hybrid

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Helal A. Ansari ◽  
Nicholas W. Ellison ◽  
Isabelle M. Verry ◽  
Warren M. Williams
Keyword(s):  
Meiotic Division ◽  
High Frequency ◽  
Molecular Mechanisms ◽  
Intergeneric Hybrids ◽  
Unreduced Gametes ◽  
Unreduced Gamete ◽  
Sister Chromatids ◽  
Gamete Formation ◽  
Normal Meiosis ◽  
Metaphase I

Abstract Background Unreduced gametes, a driving force in the widespread polyploidization and speciation of flowering plants, occur relatively frequently in interspecific or intergeneric hybrids. Studies of the mechanisms leading to 2n gamete formation, mainly in the wheat tribe Triticeae have shown that unreductional meiosis is often associated with chromosome asynapsis during the first meiotic division. The present study explored the mechanisms of meiotic nonreduction leading to functional unreduced gametes in an interspecific Trifolium (clover) hybrid with three sub-genomes from T. ambiguum and one sub-genome from T. occidentale. Results Unreductional meiosis leading to 2n gametes occurred when there was a high frequency of asynapsis during the first meiotic division. In this hybrid, approximately 39% of chromosomes were unpaired at metaphase I. Within the same cell at anaphase I, sister chromatids of univalents underwent precocious separation and formed laggard chromatids whereas paired chromosomes segregated without separation of sister chromatids as in normal meiosis. This asynchrony was frequently accompanied by incomplete or no movement of chromosomes toward the poles and restitution leading to unreduced chromosome constitutions. Reductional meiosis was restored in progeny where asynapsis frequencies were low. Two progeny plants with approximately 5 and 7% of unpaired chromosomes at metaphase I showed full restoration of reductional meiosis. Conclusions The study revealed that formation of 2n gametes occurred when asynapsis (univalent) frequency at meiosis I was high, and that normal gamete production was restored in the next generation when asynapsis frequencies were low. Asynapsis-dependent 2n gamete formation, previously supported by evidence largely from wheat and its relatives and grasshopper, is also applicable to hybrids from the dicotyledonous plant genus Trifolium. The present results align well with those from these widely divergent organisms and strongly suggest common molecular mechanisms involved in unreduced gamete formation.

Mechanisms of unreduced gamete formation in flowering plants

2017 ◽  
Vol 53 (7) ◽  
pp. 741-756 ◽  
Author(s):  
D. B. Loginova ◽  
O. G. Silkova
Keyword(s):  
Flowering Plants ◽  
Unreduced Gamete ◽  
Gamete Formation

Development of Triticum turgidum subsp. durum – Aegilops longissima amphiploids with high iron and zinc content through unreduced gamete formation in F1 hybrids

Genome ◽  
2008 ◽  
Vol 51 (9) ◽  
pp. 757-766 ◽  
Author(s):  
Vijay K. Tiwari ◽  
Nidhi Rawat ◽  
Kumari Neelam ◽  
Gursharn S. Randhawa ◽  
Kuldeep Singh ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Chromosome Pairing ◽  
Triticum Turgidum ◽  
Zinc Content ◽  
F1 Hybrids ◽  
Unreduced Gamete ◽  
Wheat Cultivars ◽  
Aegilops Longissima ◽  
Gamete Formation ◽  
Iron And Zinc

Four different interspecific hybrids involving three different accessions of Aegilops longissima Schweinf. & Muschl. with high grain iron and zinc content and three Triticum turgidum L. subsp. durum (Desf.) Husn. cultivars with low micronutrient content were made for durum wheat biofortification and investigated for chromosome pairing, fertility, putative amphiploidy, and micronutrient content. The chromosome pairing in the 21-chromosome F1 hybrids (ABSl) consisted of 0–6 rod bivalents and occasionally 1 trivalent. All the F1 hybrids, however, unexpectedly showed partial but variable fertility. The detailed meiotic investigation indicated the simultaneous occurrence of two types of aberrant meiotic divisions, namely first-division restitution and single-division meiosis, leading to regular dyads and unreduced gamete formation and fertility. The F2 seeds, being putative amphiploids (AABBSlSl), had nearly double the chromosome number (40–42) and regular meiosis and fertility. The F1 hybrids were intermediate between the two parents for different morphological traits. The putative amphiploids with bold seed size had higher grain ash content and ash iron and zinc content than durum wheat cultivars, suggesting that Ae. longissima possesses a better genetic system(s) for uptake and seed sequestration of iron and zinc, which could be transferred to elite durum and bread wheat cultivars and exploited.

scholarly journals Unreduced gamete formation in plants: mechanisms and prospects

2010 ◽  
Vol 62 (5) ◽  
pp. 1659-1668 ◽  
Author(s):  
L. Brownfield ◽  
C. Kohler
Keyword(s):  
Unreduced Gamete ◽  
Gamete Formation

scholarly journals A Review of Unreduced Gametes and Neopolyploids in Alfalfa: How to Fill the Gap between Well-Established Meiotic Mutants and Next-Generation Genomic Resources

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 999
Author(s):  
Fabio Palumbo ◽  
Elisa Pasquali ◽  
Emidio Albertini ◽  
Gianni Barcaccia
Keyword(s):  
Reverse Genetics ◽  
Gene Diversity ◽  
Unreduced Gametes ◽  
Unreduced Gamete ◽  
Next Generation ◽  
Gene Characterization ◽  
Meiotic Mutants ◽  
Genomic Resources ◽  
Gamete Formation ◽  
2N Gamete

The gene flow mediated by unreduced gametes between diploid and tetraploid plants of the Medicago sativa–coerulea–falcata complex is pivotal for alfalfa breeding. Sexually tetraploidized hybrids could represent the best way to exploit progressive heterosis simultaneously derived from gene diversity, heterozygosity, and polyploidy. Moreover, unreduced gametes combined with parthenogenesis (i.e., apomixis) would enable the cloning of plants through seeds, providing a unique opportunity for the selection of superior genotypes with permanently fixed heterosis. This reproductive strategy has never been detected in the genus Medicago, but features of apomixis, such as restitutional apomeiosis and haploid parthenogenesis, have been reported. By means of an original case study, we demonstrated that sexually tetraploidized plants maintain apomeiosis, but this trait is developmentally independent from parthenogenesis. Alfalfa meiotic mutants producing unreduced egg cells revealed a null or very low capacity for parthenogenesis. The overall achievements reached so far are reviewed and discussed along with the efforts and strategies made for exploiting reproductive mutants that express apomictic elements in alfalfa breeding programs. Although several studies have investigated the cytological mechanisms responsible for 2n gamete formation and the inheritance of this trait, only a very small number of molecular markers and candidate genes putatively linked to unreduced gamete formation have been identified. Furthermore, this scenario has remained almost unchanged over the last two decades. Here, we propose a reverse genetics approach, by exploiting the genomic and transcriptomic resources available in alfalfa. Through a comparison with 9 proteins belonging to Arabidopsis thaliana known for their involvement in 2n gamete production, we identified 47 orthologous genes and evaluated their expression in several tissues, paving the way for novel candidate gene characterization studies. An overall view on strategies suitable to fill the gap between well-established meiotic mutants and next-generation genomic resources is presented and discussed.

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