1991 Fiscal Year Final Research Report Summary
Distribution and differentiation of ectopic germ cells in mouse, chick and quail embryos.
| Project/Area Number |
02807005
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | Kumamoto University |
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Principal Investigator |
YOSHINAGA Kazuya Kumamoto University Medical School/Anatomy/Assistant, 医学部, 助手 (50136719)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIMOTO Toyoaki Kawasaki College of Allied Health Professions/Professor, 教授 (00040139)
YASUDA Yoshiaki Kumamoto Univ. Med. Sch. /Anatomy/Assistant, 医学部, 助手 (10128324)
NAKAMURA Masao Kumamoto Univ. Med. Sch. /Anatomy/Assistant, 医学部, 助手 (10180390)
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| Project Period (FY) |
1990 – 1991
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| Keywords | primordial germ cells / ectopism / cell migration / germ cell differentiation / germline chimeras / mouse fetus / chick embryo / quail embryo |
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| Research Abstract |
Primordial germ cells(PGC)migrate from extragonadal sites into the gonadal ridge where they differentiate into definitive male or female germ cells. However, some of the PGC deviate from their normal migratory route and become located in ectopic sites. This study was carried out to investigate the distribution and fate(differentiation)of such ectopic PGC in mouse, chick and quail embryos/fetuses.
[1] Ectopic PGC in mouse fetuses : Mouse PGC were identified with a new immunohistochemical procedure for 4C9 monoclonal antibody. observations were made both by light and electron microscopy. Ectopic PGC were detected in the tissue between the aorta and cardinal vein, the retroperitoneal neuroganglia and the adrenals. It was found that some of these ectopic PGC both in male and female fetuses entered the prophase of meiosis at the same time as they did in the fetal ovary. These findings suggest that mouse germ cells are capable of developing even outside the gonads, and that in ectopic sites t
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hey differentiate into as oocytes irrespective of their genetic sex.
[2] Ectopic colonization of chick and quail PGC : We used new histochemical procedures for STA and WFA lectins to identify chick and quail PGC, respectively. In each embryo of both species of chick and quail, approximately 10-20% of total number of PGC were found in ectopic sites, mostly in the head mesenchyme of the embryo.
[3] An approach to know mechanisms for ectopic migration of PGC : The following experiments were carried out, using the avian embryos in which the PGC circulate temporarily through the blood vascular system. (1) Embryonic chick (or quail) blood including PGC was injected into the blood stream of quail (or chick) embryo. When the injection was done after finishing the settlement of recipient PGC, the donor PGC became distributed in extragonadal sites of the recipient. (2) Isolation of PGC was performed using Ficoll density centrifugation ; 500-600 PGC were obtained from 20 embryos within 2.5 hr. Every 100 PGC (donor) were injected to the blood channel of recipient quail embryo. After 24 hr of incubation, 39.3<plus-minus>4.5 donor PGC were found in the recipient gonadal anlag
[4]The results herewith obtained indicate that avian PGC can be transferred by a intravascular route for analyzing the mechanisms of PGCectopism and for the production of germline chimeras. Less
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