Pachytene stage

Hlt/HILS Testis-specific Mid-pachytene stage of meiosis RI ... 

In the mid-pachytene stage of meiosis. Hit becomes preferentially enriched in testicular cells and contributes to up to 50% of the total chromosomal linker histones (Cole et al. 1986). The deletion of Hit has no effect on viability and fertility of mice (Drabent et al. 2000). It is not quite clear whether other HI variants are upregulated in pachytene spermatocytes of Hit-deficient animals and compensate for the loss of Hit (Drabent et al. 2003 Nayernia et al. 2005). Thus, very little is known about... 

Hoyer-Fender, S., Costanzi, C., and Pehrson, J.R. (2000) Histone macroH2A1.2 is concentrated in the XY-body by the early pachytene stage of spermatogenesis. Exp. Cell Res. 258, 254-260. 

Upper Left A pair of mitotic sister chromatids in a section stained with an antibody to topoisomerase II. Notice that the two chromatids are coiled with opposite helical handedness. Lower Left Meiotic chromosomes of a lily at the pachytene stage in which sister chromatids are connected along their length in a synaptonemal complex. From Kleckner, N. (1996) Proc. Natl. Acad, Sci U.S.A. 93, 8167-8174... 

During the prophase of the first meiotic division (meiosis I) two homologous pairs of partially "condensed" chromosomes must find each other and pair with appropriate orientation. A protein in the telomeres of the chromosomes seems to be involved.269 277 The key structure in meiotic crossing-over is the ribbonlike synaptonemal complex formed by the pairs of homologous chroma fids.271/278 2791 This complex, in which a proteinaceous core or axial element separates the greatly extended chromatid pairs (Fig. 26-13), is fully formed in the pachytene stage of meiosis. Formation of the synaptonemal complex is preceded by development of a few double-stranded breaks in... 

Kawamata, M. Nishimori, K (2006). Mice deficient in DMRT7 show infertility with spermatogenic arrest at pachytene stage. FEBS letters, Vol.580, No.27, pp. 6442-6446, ISSN 0014-5793... 

Fig. 5. In situ hybridization of radioactive rRNA with cytological preparations from the ovary of Xenopus laevis. (A) Oogonial stages with a few silver grains located over the centrally placed nucleolus (arrow). X 1275. (B) Two nuclei from leptotene stage oocytes showing a few silver grains over the eccentrically placed nucleoli (arrows). X 1275. (C) Three small unlabeled follicle nuclei and three larger heavily labeled nuclei from pachytene stage oocytes. X1020. [By courtesy of Dr. J. G. Gall, reprinted from Proc. Nat. Acad. Set. 17.S. 63, 378 (1969).]...

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