Interchromosomal connections in meiosis of Secale cereale

Viinikka, Yrjö; Nokkala, Seppo

doi:10.1111/j.1601-5223.1981.tb01410.x

Cited by 12 publications

(7 citation statements)

References 19 publications

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“…Achiasmate meiosis and inter-chromosomal connections have been reported separately in a number of plant species [13,16,39,65] and no report is available on the presence of these two cytological manifestations together in a single species. As such the present report of the presence of achiasmate meiosis coupled with inter-telomeric connections is the first report for T. spathacea.…”

Section: Discussionmentioning

confidence: 98%

“…As such the present report of the presence of achiasmate meiosis coupled with inter-telomeric connections is the first report for T. spathacea. While inter chromosomal connections have been attributed mostly to fixation artifact [33] and to the fusion of heterochromatic region between the chromosomes [16,39,62,65], achiasmate meiosis has been assigned to the presence of mutant gene(s) affecting chiasmata formation [2,21,32,34,60], alteration in temperature/humidity [34,60,67], defective synaptonemal complex formation [14,21,24,60] and to disturbed supply of potassium and phosphate ions to the tissue [2,60]. In the present material inter-telomeric connections cannot be attributed to any of the two factors mentioned elsewhere on account of the fact that this feature was discerned only in some buds while other buds showed meiotic features characteristic of complex translocation heterozygote and supported the earlier reports [17,18,31,36,37,41,42,55,56,64].…”

Section: Discussionmentioning

confidence: 99%

“…Interconnections joining homologous or non homologous chromosomes, wherever observed earlier, were not taken seriously and were regarded mostly as fixation artifacts [33]. However, of late its presence has been reported in a number of animals and plants and its possible role in the regular congression of chromosomes, that ensures eventual proper segregation, has been stressed [3,16,28,30,33,38,39,63,65,69]. During the present course of investigations inter chromosomal connections, joining the telomeric ends of the chromosomes, were observed in a plant of Tradescantia spathacea Sw. while familiarizing the students with the complex chromosomal configurations formed during meiosis I of this complex translocation heterozygote.…”

Section: Introductionmentioning

confidence: 97%

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Inter-telomeric connections and achiasmate meiosis in Tradescantia spathacea Sw.

Koul

Nagpal

2016

Nucleus

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While demonstrating chromosome ring and chain configurations formed during meiosis I of permanent translocation heterozygote Tradescantia spathacea Sw. (syn. Rhoeo spathacea; 2n = 2x = 12) to a group of students, two different patterns of chromosome behavior were observed for the first time in various buds of this plant. While in some buds meiosis was characterized by the presence of chain multiples of varying lengths with chromosomes in each configuration joined exclusively by terminal chiasmata, meiosis in the other set of buds was conspicuous in that the chain configurations, wherever observed, did not have any chiasmata. The achiasmate chromosomes were held in chain configurations exclusively by thin inter-telomeric connections which occasionally span the whole cell. These connections were prominent at early prophase stage and by the time meiotic stage progressed to diplotene the connections had disappeared leaving all the 12 chromosomes scattered at diplotene and the ensuing meiotic stages. The behavior of chromosomes was typical of a desynaptic-mutant. The anaphase I was highly erratic and in 96.70 % cells 1-6 lagging chromosomes were observed which later appeared as micronuclei in 58.90 % cells. It is proposed that some alteration in the cellular microenvironment probably altered the telomeric architecture that not only impeded the chiasmata formation but also induced ectopic pairing through inter-telomeric connections.

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Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

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Inter-telomeric connections and achiasmate meiosis in Tradescantia spathacea Sw.

Koul

Nagpal

2016

Nucleus

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“…Koduru and Rao (1981) and Bione et al (2000) indicated that the behavior of abnormal chromosomal segregation and laggard may lead to micronucleus formation. According to Viinikka and Nokkala (1981), the fusion of heterochromatic regions of some of the chromosomes early in the first meiotic division probably resulted in the formation of chromatic knots, which lead to the formation of prominent inter-connections that were observed at various stages of meiosis. These authors are also of the opinion that the main function of the interconnections is to keep the bivalents in contact with each other before the spindle fibers are formed, in order to guarantee the proper movements and orientation of the chromosomes in division plane.…”

Section: Discussionmentioning

confidence: 99%

Irregular Meiotic Behaviour in Maidenhair Fern <i>Adiantum capillus-veneris</i> L. from Northwest India

Saggoo

Kaur

2016

CYTOLOGIA

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SummaryThe present research has been carried out on Adiantum capillus-veneris L., a well renowned medicinal fern, to study its detailed meiotic behaviour in 14 populations collected from different parts of Northwest India. All the populations uniformly revealed the presence of 30 bivalents at M-I as reported by previous workers. However, irregular meiotic behaviour characterized by the presence of stickiness, unoriented bivalents, laggards, bridges, interbivalent connections, secondary associations, cytomixis, formation of micronuclei leading to abnormal microsporogenesis, i.e., spore sterility, were investigated. The abnormal meiotic course in some studied populations has a significant effect on spore viability, i.e., reduced spore fertility. To our knowledge, this is the first ever population based report on abnormal meiotic behaviour of this species.

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“…This would be necessary, however, before bands could be used effectively in karyotype analysis. Using the C-band staining method developed by Nokkala (Viinikka and Nokkala 1981), on the basis of the technique of Weimarck (1974), faint but distinct transverse bands were obtained marking the centromere region of each chromosome and mostly appearing as two separate dots (Fig. 4).…”

Section: Chromosome Numbersmentioning

confidence: 99%

Chromosomes and reproductive behaviour of Finnish Taraxacum agamospecies

Rousi

Huttunen

Hyrkäs‐Lyytikäinen

1985

Nordic Journal of Botany

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Hyrkas-Lyytikainen, K. 1984. Chromosomes and reproductive behaviour of Finnish Taraxacurn agamospecies. -Nord. J. Bot. 5: 127-141. Copenhagen. ISSN 0107-055X.Material consisting of 157 accessions of 69 Finnish Taraxacum agamospecies, representing 7 sections, was grown in an experimental field for comparison of certain botanical and nutritional characteristics. This paper gives the collecting data as well as cytological and reproductive characteristics of the material. The largest section Taruxacum (Vulgariu) was represented by 60 agamospecies, 59 of them triploid (2n = 24) and one tetraploid (T. penicilliforme, 2n = 32). The tetraploid and 37 triploids were chromosome counted for the first time. The diploid sexual species T. obtusilobum from Sweden was included for comparison. Other sections consisted of 3 triploids and 6 tetraploids, 3 tetraploid species of the section Erythrosperma being chromosome counted for the first time. Seedlings with deviating numbers were occasionally found. A banding technique of the chromosomes was developed but it did not allow the exact identification of other than the satellite chromosomes. Species-specific features were found in the flowering phenology and in several pollen characteristics (stainability, mean and variability of the size). There were indications of genetic variation within certain agamospecies in pollen characteristics. Isolated and emasculated (mostly only isolated) flower heads gave mostly a full seed set, which indicates obligate, autonomous agamospermy. Lower seed sets of T. adami, T. dahlstedtii and T. hamatiforme in isolation may be a sign of facultative apomixis in these species, requiring further study.

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Interchromosomal connections in meiosis of Secale cereale

Cited by 12 publications

References 19 publications

Inter-telomeric connections and achiasmate meiosis in Tradescantia spathacea Sw.

Inter-telomeric connections and achiasmate meiosis in Tradescantia spathacea Sw.

Irregular Meiotic Behaviour in Maidenhair Fern <i>Adiantum capillus-veneris</i> L. from Northwest India

Chromosomes and reproductive behaviour of Finnish Taraxacum agamospecies

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