Talk:Spermatozoa Meiosis Movie 1
The dissection of meiotic chromosome movement in mice using an in vivo electroporation technique
PLoS Genet. 2014 Dec 11;10(12):e1004821. doi: 10.1371/journal.pgen.1004821. eCollection 2014.
Shibuya H1, Morimoto A1, Watanabe Y1.
During meiosis, the rapid movement of telomeres along the nuclear envelope (NE) facilitates pairing/synapsis of homologous chromosomes. In mammals, the mechanical properties of chromosome movement and the cytoskeletal structures responsible for it remain poorly understood. Here, applying an in vivo electroporation (EP) technique in live mouse testis, we achieved the quick visualization of telomere, chromosome axis and microtubule organizing center (MTOC) movements. For the first time, we defined prophase sub-stages of live spermatocytes morphologically according to GFP-TRF1 and GFP-SCP3 signals. We show that rapid telomere movement and subsequent nuclear rotation persist from leptotene/zygotene to pachytene, and then decline in diplotene stage concomitant with the liberation of SUN1 from telomeres. Further, during bouquet stage, telomeres are constrained near the MTOC, resulting in the transient suppression of telomere mobility and nuclear rotation. MTs are responsible for these movements by forming cable-like structures on the NE, and, probably, by facilitating the rail-tacking movements of telomeres on the MT cables. In contrast, actin regulates the oscillatory changes in nuclear shape. Our data provide the mechanical scheme for meiotic chromosome movement throughout prophase I in mammals.
PMID 25502938 PMCID: PMC4263375 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4263375/
DOI: 10.1371/journal.pgen.1004821 http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004821
The meiotic specific synaptonemal complex protein SCP3 is expressed by female and male primordial germ cells of the mouse embryo
Int J Dev Biol. 2000 Feb;44(2):241-4.
Di Carlo AD1, Travia G, De Felici M.
The synaptonemal complex proteins SCP3 and SCP1 are components of the synaptonemal complex, a meiosis-specific protein structure essential for synapsis of homologous chromosomes. Using polyclonal antibodies raised against SCPs of rat testis, we have studied the expression of these proteins in embryonic germ cells of the mouse embryo using immunohistochemistry and immunoblotting. This investigation provided the first description of the sequential appearance of SCP3 and SCP1 during the different stages of the female meiosis in the mouse. Most importantly, we found that also male primordial germ cells express SCP3 for a short time before undergoing G1 arrest. This strongly supports the hypothesis that primordial germ cells are programmed to enter meiosis unrespective of the sex and that foetal testis produces a factor that inhibits such programme.