Techniques are now available for the study of meiosis in the human female through the short term culture of oocytes from ovaries. One cell, in which 23 bivalents could be distinguished, shows interstitial chiasmata in the bivalents, in which all four strands can be distinguished. The small ...
the cost of “males”, as male individuals do not produce offspring; asexual animals are thus expected to produce higher quantities of offspring than sexual ones. In animals, where separate sexes are the rule (ie. male and female individuals), the cost of males is regarded as a major ...
Asparagus officinalis (garden asparagus) is a dioecious perennial crop, and the dioecy (i.e., sex) of A. officinalis can affect its productivity. In A. officinalis, flower anthers in female plants fail to accumulate callose around microsporocytes, fail t
The 24-nt reproductive phasiRNAs are triggered by miR2275, and are highly enriched during meiosis in many angiosperms. Here, we report the widespread presence of the 21-nt reproductive phasiRNA pathway in eudicots including canonical and non-canonical microRNA (miRNA) triggers of this pathway. ...
(meiosis arrest female 1) as a protein essential for controlling meiosis and retrotransposon surveillance in oocytes; and in contrast to PIWI-pathway mutations, Marf1 mutant females are infertile, whereas mutant males are fertile. Here we put forward the hypothesis that MARF1 in mouse oocytes is ...
The goal of our study was to identify genes connected to female gametophyte development and archegonia production in the dioecious liverwort Pellia endiviifolia species B, which is representative of the most basal lineage of the simple thalloid liverworts. Results The utility of the RDA-cDNA ...
Isochromosome 18p Results from Maternal Meiosis II Nondisjunction Microsatellite analysis with 13 microsatellites spread over 18p was performed to determine the origin of the marker chromosome in 9 patients with additiona... D Kotzot,G Bundscherer,F Bernasconi,... - 《European Journal of Human Genet...
In mammalian meiotic prophase, homologous chromosome recognition is aided by formation and repair of programmed DNA double-strand breaks (DSBs). Subsequently, stable associations form through homologous chromosome synapsis. In male mouse meiosis, the lar
The X+4 chromosome can thus be regarded as a 'neo-X', and the 1p+4 as a 'neo-Y' chromosome, because of probable lack of recombination in the inverted region. Figure 1 Neo-sex chromosomes of Muntiacus crinifrons. (a) Paring patterns in male and female black muntjacs during meiosis. ...
Sex determination mechanisms often differ even between related species yet the evolution of sex chromosomes remains poorly understood in all but a few model organisms. Some nematodes such as Caenorhabditis elegans have an XO sex determination system whil