In S. pombe, about 5% of genes are meiosis-specific and accumulate little or no mRNA during vegetative growth. Here we use Affymetrix tiling arrays to characterize transcripts in vegetative and meiotic cells. In vegetative cells, many meiotic genes, especially those induced in mid-meiosis, have abundant antisense transcripts. Disruption of the antisense transcription of three of these mid-meiot...

Background: Infertility is increasingly recognized as a major health problem. Meiotic genes are very important candidates for genes contributing to female and male infertility. Mammalian MutL homologues have dual roles in DNA mismatch repair (MMR) after replication errors and meiotic reciprocal recombination. There are four MutL homologues in eukaryotes that mutations of three of them (Mlh1, Ml...

To transfer multiple desirable alien genes into common wheat, we previously reported a new trigeneric hybrid synthesized by crossing a wheat - Thinopyrum intermedium partial amphiploid with wheat - Psathyrostachys huashanica amphiploid. Here, the meiotic behavior, chromosome constitution, and stripe rust resistance of F5 derivatives from the wheat - Th. intermedium - P. huashanica trigeneric hy...

The t(11;22)(q23;q11) translocation is the only non-Robertsonian rearrangement for which there are a large number of unrelated families, apparently with the same breakpoints. These families most often have been ascertained through an abnormal child with the karyotype 47,XX or XY, +der(22) t(11;22)(q23;q11). To explain the high incidence of 3:1 segregants, rarely seen in offspring of carriers of...

At meiotic prophase, the grasshopper Chorthippus longicornis has normal synaptinemal complexes inside paired homologous chromosomes. Evidence is presented that short single cores and small multiple core complexes occur inside metaphase I chromosomes. At first anaphase, interphase, and early spermatid stage, large multiple core complexes are located in the cytoplasm. It is speculated that the mu...

During the early stages of meiosis in Neurospora, the symmetry of homologous chromosomal regions is carefully evaluated by actively trans-sensing their identity. If a DNA region cannot be detected on the opposite homologous chromosome, then this lack of "sensing" activates meiotic silencing, a post-transcriptional gene silencing-like mechanism that silences all genes in the genome with homology...

In humans, the frequency with which meiotic chromosome mis-segregation occurs increases with age. Whether age-dependent meiotic defects occur in other organisms is unknown. Here, we examine the effects of replicative aging on meiosis in budding yeast. We find that aged mother cells show a decreased ability to initiate the meiotic program and fail to express the meiotic inducer IME1. The few age...

Budding yeast Pch2 protein is a widely conserved meiosis-specific protein whose role is implicated in the control of formation and displacement of meiotic crossover events. In contrast to previous studies where the function of Pch2 was implicated in the steps after meiotic double-strand breaks (DSBs) are formed, we present evidence that Pch2 is involved in meiotic DSB formation, the initiation ...

....................................................................................................................... vi Chapter 1: Introduction .............................................................................................. 1 The switch between the mitotic and meiotic transcriptome ................................ 2 Regulatory processing of meiotic transcripts ...................

Eleven populations of five Avena species were analysed for meiotic characters including chiasma frequency and distribution as well as chromosomal association and segregation. Plants of a single population of A. eriantha showed the presence of 2n = 14 (diploid) and 2n = 4x = 28 chromosome number. Populations of A. barbata and A. wiestii possessed n = 14, while populations of A. sterilis ssp. lud...