Cytomixis in Pollen Mother Cells of Diploid Dactylis, One of the Origins of 2n Gametes

Falistocco, Egizia; Tosti, Nicola; Falcinelli, M.

doi:10.1093/oxfordjournals.jhered.a111619

Cited by 153 publications

(130 citation statements)

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“…The phenomenon of cytomixis in the species does not seem to have affected the pollen fertility percentage but has resulted into the formation of heterogenous sized pollen grains. Similar results regarding the high pollen fertility in plants depicting cytomixis were reported in Dactylis by Falistocco et al (1995). These apparently fertile heterogenous sized pollen grains are the products of cytomictic PMCs (hypo-and hyperploid) as demonstrated by Ghaffari (2006) in Sorghum bicolor.…”

Section: Discussionsupporting

confidence: 80%

“…The cytomixis in such cases resulted in the formation of hypo-hyperploid and anucleated PMCs besides including various meiotic irregularities. Cytomixis as a cause of inducing meiotic irregularities and formation of hypo-and hyperploid PMCs has also been reported in several plants (Omara 1976, Singhal and Gill 1985, Dagne 1994, Falistocco et al 1995, Ghanima and Talaat 2003, Ghaffari 2006. The chromatin transfer in the species seems to cause disturbances in spindle apparatus resulting in the formation of dyads, triads and polyads.…”

Section: Discussionmentioning

confidence: 89%

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Effect of Cytomixis on the Pollen Size in 'Seabuckthorn' (Hippophae rhamnoides L., Elaeagnaceae)

2008

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Summary Present study reveals the occurrence of inter PMC transfer of chromatin material in the PMCs of 'Seabuckthorn' (Hippophae rhamnoides L.). The migration of chromatin is observed from early prophase up to telophase-I. In majority of the cases 2-4 PMCs are involved in chromatin transfer, however in rare occasions migration of chromatin occurs in groups. The migration of chromatin is observed to be partial as well as complete, which resulted into the formation of anucleated, hypo and hyperploid PMCs. In rare cases, direct fusion between two PMCs at AI lead to the formation of a polyploid PMC with 36 chromosomes. As a consequence of cytomixis various other associated meiotic anomalies such as chromatin stickiness at MI and late disjunction of bivalents at AI, pycnotic chromatin, bridges and laggards at anaphases and telophases are resulted. Microsporogenesis is also abnormal resulting in the formation of dyads, triads, and polyads with micronuclei. The cytomixis though do not cause much pollen sterility but it surely results in the formation of heterogenous sized fertile pollen grains. The pollen grains are classified into small, medium and large sized with medium sized pollen grains being in high frequency. The role of such fertile, especially, small and large sized pollen grains, in the origin of plants with aneuploid and polyploid chromosome number, can not be ruled out. The present meiotic count of nϭ9 is the first record for the study area.

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Section: Discussionsupporting

confidence: 80%

Section: Discussionmentioning

confidence: 89%

Effect of Cytomixis on the Pollen Size in 'Seabuckthorn' (Hippophae rhamnoides L., Elaeagnaceae)

2008

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“…Some authors suggested that chromatin and chromosome migration is not random but directional. For example, Falistocco et al (1995) observed that, in Dactylis, cytomixis always occurred from a donor to a receptor cell and that, in several cases, complete or almost total genetic material migration occurred not only between two cells, but also amongst several cells at the same time. Pesq.…”

Section: Resultsmentioning

confidence: 99%

Abnormal meiotic behavior in three species of Crotalaria

Ferreira

Torres

Carvalho

et al. 2009

Pesq. agropec. bras.

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-The objective of this work was to compare the meiotic behavior and pollen grain viability of three species of Crotalaria. Slides for meiotic analysis were prepared by the air-drying technique. Pollen grain viability was measured by three staining procedures (Alexander's solution, tetrazolium chloride and fl uorescein diacetate) and in vitro germination in a sucrose solution. Eight bivalents were observed, confi rming previous reports on populations from other regions of Brazil, as well as from other countries. All species showed abnormal meiotic behavior as follows: in Crotalaria micans, cytomixis and abnormal chromosome pairing in diakinesis; in C. spectabilis, abnormal chromosome pairing in diplotene; in C. zanzibarica, shrunk nuclei in leptotene and zygotene. Pollen grains of all three species show low viability, which may be associated with the irregularities of the meiotic behavior.Index terms: Crotalaria, cytogenetics, cytomixis, meiosis, pollen grain viability. Comportamento meiótico anormal em três espécies de CrotalariaResumo -O objetivo deste trabalho foi comparar o comportamento meiótico e a viabilidade dos grãos de pólen de três espécies de Crotalaria. A análise meiótica foi realizada por meio da técnica de secagem ao ar. A viabilidade dos grãos de pólen foi avaliada por testes de coloração (corante de Alexander, cloreto de tetrazólio e diacetato de fl uoresceína) e por teste de germinação em solução de sacarose. Foram observados oito bivalentes, confi rmando relatos prévios em populações de outras regiões do Brasil e de outros países. As três espécies apresentaram comportamento meiótico irregular: em Crotalaria micans, citomixia e pareamento irregular na diacinese; em C. spectabilis, pareamento irregular no diplóteno; e em C. zanzibarica, núcleo fortemente condensado nas fases de leptóteno e zigóteno. A viabilidade dos grãos de pólen das três espécies é baixa, o que pode estar associado às irregularidades do comportamento meiótico.Termos para indexação: Crotalaria, citogenética, citomixia, meiose, viabilidade do grão de pólen.

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“…Presumably, their fundamental role is in the transfer of part of genetic material from one cell to another via cytomixis resulting in an increase in genetic diversity of the produced pollen or an adjusting and balancing in unbalanced genomes (Falistocco et al 1995;Zhou 2003;Ghaffari 2006;Lattoo et al 2006;Negron-Ortiz 2007;Singhal and Kumar 2008;Song and Li 2009;Singhal et al 2011).…”

Section: Causes and Consequencesmentioning

confidence: 99%

“…The most important mechanism leading to polyploid plants is formation of the gametes with a diploid chromosome number (Bretagnolle and Thompson 1995). Diploid gametes can be produced in several ways, and cytomixis might well be one of them (Falistocco et al 1995;Ghaffari 2006;Lattoo et al 2006). On the other hand, cytomixis may be involved in elimination of the "surplus" DNA by discharging part of the chromatin from the nucleus to the cytoplasm of another cell, thereby providing for either stabilization of a polyploid genome or return from a polyploid to a diploid state (Cheng et al 1987;Baptista-Giacomelli and Pagliarini 2000;Zhou 2003;Kalinka et al 2010).…”

Section: Causes and Consequencesmentioning

confidence: 99%

New insights into cytomixis: specific cellular features and prevalence in higher plants

Mursalimov

Sidorchuk

Дейнеко

2013

Planta

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Cytomixis in Pollen Mother Cells of Diploid Dactylis, One of the Origins of 2n Gametes

Cited by 153 publications

References 0 publications

Effect of Cytomixis on the Pollen Size in 'Seabuckthorn' (Hippophae rhamnoides L., Elaeagnaceae)

Effect of Cytomixis on the Pollen Size in 'Seabuckthorn' (Hippophae rhamnoides L., Elaeagnaceae)

Abnormal meiotic behavior in three species of Crotalaria

New insights into cytomixis: specific cellular features and prevalence in higher plants

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