Epigenetics of the Synaptonemal Complex
نویسندگان
چکیده
Meiosis is a process composed of two divisions of the germ line cells without an intervenient S phase, thus there is no duplication of DNA between the first and the second meiotic divisions. The first meiotic division begins with the pre-leptotene that is the stage where the DNA replicates and chromosomes prepare to enter the meiotic prophase I in most of the organisms with sexual reproduction (Marston & Amon, 2004). The first meiotic division separates one homologue chromosome from the other member of the pair and in this way the two produced cells contain half number of chromosomes with two chromatids. During the metaphase of the first meiotic division the maternal and the paternal chromosomes of the bivalents are oriented at random, so the two new haploid cells receive a random number of chromosomes of each progenitor.
منابع مشابه
P-223: Analysis of Synaptonemal Complex Gene Disorders Involving in Recurrent Spontaneous Abortion
Background: Spontaneous abortion (SAb) is the most common complication of early pregnancy. Numerous risk factors are associated with an increased risk of pregnancy loss such as: Maternally age, previous spontaneous abortion, prolonged ovulation to implantation, Gravidity, Interval Prolonged time to pregnancy, Balanced chromosomal translocations and Genetic disorders. The aim of this study was t...
متن کاملP-198: Analysis of Expression Level of TEX12 Gene in Testis Tissues of Severe Oligozoospermic and Non-Obstructive Azoospermic Men
Background: During the first meiotic prophase, alignment and synapsis of the homologous chromosomes are mediated by the synaptonemal complex. Incorrect assembly of the synaptonemal complex leads to impaired recombination and cell death, which in humans, causes infertility in males. Testis-expressed gene 12 (TEX12) is a germ cell-specific gene that is located on the chromosome 11 (11q22) in huma...
متن کاملThe Role and Effect of Hspa2 in Male Infertility
The heat shock proteins (HSPs) are a group of homologous proteins encoded with a multigene family. They can be divided into five groups based on both size and function; including HSP27, HSP60, HSP70, HSP90 and HSP100. Expression of HSPs can be constitutive and can increased when cells undergo metabolic and/or heat stress. HSPA2/Hsp70-2 is a kind of HSP70 and constitutively expressed in testis. ...
متن کاملTwo novel proteins recruited by synaptonemal complex protein 1 (SYCP1) are at the centre of meiosis.
Completion of meiosis in mammals depends on the formation of the synaptonemal complex, a tripartite structure that physically links homologous chromosomes during prophase I. Several components of the synaptonemal complex are known, including constituents of the cohesin core, the axial/lateral element and the transverse filaments. No protein has previously been identified as an exclusive compone...
متن کاملSolving a meiotic LEGO puzzle: transverse filaments and the assembly of the synaptonemal complex in Caenorhabditis elegans.
The structure of the meiosis-specific synaptonemal complex, which is perhaps the central visible characteristic of meiotic prophase, has been a matter of intense interest for decades. Although a general picture of the interactions between the transverse filament proteins that create this structure has emerged from studies in a variety of organisms, a recent analysis of synaptonemal complex stru...
متن کاملSynaptonemal complexes during premeiotic DNA synthesis in oocytes of Drosophila melanogaster.
Well-synchronized populations of oocytes obtained by means of the "pupal system" (Grell, 1973a) have been examined to determine the time of appearance of the synaptonemal complex. The complex first appears in the most advanced oocytes between 132 and 138 hr of female development. Between 138 and 156 hr the complex apparently undergoes a fourfold increase in length. At 150 and 156 hr the complex...
متن کامل