Germ cell development

Abnormal Germ Cell Development and Testicular Cancer... 

Evidence for the involvement of a Cdc2/Cyc B complex in the mitotic stages of germ cell development comes from studies in Drosophila. Cyc B transcripts are abundant and uniformly distributed in the early Drosophila embryo (Whitfield et al., 1989, 1990 Lehner and O Farrell, 1990b). Maternally derived Cyc B transcripts are also concentrated at the posterior pole of the oocyte. Later, during embryogenesis, Cyc B tran-... 

The highly restricted tissue-specific transcription of c-mos poses an interesting problem in gene regulation during germ cell development. Moreover, c-mos is transcribed from different promoters in mouse spermatocytes and oocytes (Fig. 4) (Propst et al., 1987). In spermatocytes, transcription initiates approximately 280 nucleotides upstream of the c-mos ATG (Propst et al., 1987), whereas the transcription start site in oocytes has been mapped to 53 base pairs upstream of the ATG (Pal et al., 1991). Neither the spermatocyte nor oocyte promoter regions are... 

Dominant lethal assays in mice were performed using o- and p-cresols. Male mice were given a single dose of o-cresol (0, 75, 250, or 750 mg/kg) or p- cresol (0, 100, 275, or 550 mg/kg) by gavage in corn oil and mated to untreated females in order to assess dominant lethal effects. The matings were continued for 6 weeks so that all stages of male germ cell development were tested. 

Lee J, Inoue K, Ono R, Ogonuki N, Kohda T, Kaneko-Ishino T, Ogura A, Ishino F. Erasing genomic imprinting memory in mouse clone embryos produced from day 11.5 primordial germ cells. Development 2002 129 1807— 1817. 

Dominant lethal tests are usually conducted in mice or rats. The mouse dominant lethal test is more economical, but the rat dominant lethal test is more informative, as corpora lutea may be accurately enumerated in pregnant female rats, but not in mice, to assess preimplantation loss. Although dominant lethal tests may be performed with treated females, the tests are commonly performed with treated males in order to identify stages sensitive to mutation induction during germ cell development because the knowledge of stage sensitivity is important for risk evaluation. In a typical dominant lethal test, males... 

It is enclosed in a tough fibrous capsule called the tunica albuginea (Figure 2). Within the seminiferous tubules, germ cells develop into spermatozoa in a process called spermatogenesis. The Leydig cells located between tubules in the testis interstitium... 

The Sertoli cell plays a key metabolic role in the processes of germ cell development. Compounds that disrupt Sertoli cell metabolism would be expected to cause testicular toxicity. For example, 1,3-dinitro-benzene and other nitroaromatic compounds cause testicular toxicity apparently by disruption of Sertoli cell function. These compounds can undergo reductive metabolism to toxic nitroso intermediates, which may be ultimately responsible for the Sertoli cell toxicity. As indicated above, microtubules play an important role in support and transport processes. Hexanedione has been studied extensively as an agent capable of altering testicular microtubules. Other compounds that disrupt microtubule assembly and Sertoli cell function include the fungicide ben-omyl and the antiinflammatory agent colchicine, both of which prevent the assembly of testicular tubulin into microtubules. 

MacGregor GR, Zambrowicz BP, Soriano P (1995) Tissue non-specific alkaline phosphatase is expressed in both embryonic and extra-embryonic lineages during mouse embryogenesis but is not required for migration of primordial germ cells. Development 121 1487-1496... 

Otala, M., Pentikainen, M. O., Matikainen, T., Suomalainen, L., Hakala, J. K., Perez, G. I., Tenhunen, M., Erkkila, K., Kovanen, P., Parvinen, M. Dunkel, L. Effects of acid sphingomyelinase deficiency on male germ cell development and programmed cell death. Biol Reprod 72 (2005) 86-96. 

Raz, E. (2003) Primordial germ-cell development the zebrafish perspective. Nat. Rev. Genet. 4, 690-700. 

O Reilly AM, Ballew AC, Miyazawa B, Stocker H, Hafen E, Simon MA. 2006. Csk differentially regulates Src64 during distinct morphological events in Drosophila germ cells. Development 133(14) 2627-2638. 

Donovan PJ (1994) Growth factor regulation of mouse primordial germ cell development. Curr Top Dev Biol. 29 189-225. 

---