Characterization of definitive lymphohematopoietic stem cells in the day 9 murine yolk sac.
The site of origin of lymphohematopoietic stem cells (HSC) that initiate definitive blood cell production in the murine fetal liver is controversial. Contrary to reports that the preliver yolk sac does not contain definitive HSC, we observed that CD34+ day 9 yolk sac cells repopulated multiple blood cell lineages in newborn hosts for at least 1 year. Furthermore, 100 CD34+c-Kit+ day 9 yolk sac or para-aortic splanchnopleura (P-Sp) cells, known to give rise to embryonic HSC, similarly repopulated hematopoiesis in recipient hosts. Surprisingly, 37-fold more CD34+c-Kit+ cells reside in the day 9 yolk sac than in the P-Sp. In sum, definitive HSC are coexistent, but not equal in number, in the murine yolk sac and P-Sp prior to fetal liver colonization.
Yoder
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MC
Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis 46202, USA.
Hiatt
K
K
Dutt
P
P
Mukherjee
P
P
Bodine
D M
DM
Orlic
D
D
D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D005260:Female; D005333:Fetus / Q000378:metabolism; D006133:Growth Substances / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D008099:Liver / Q000196:embryology; D051379:Mice; D010641:Phenotype; D011247:Pregnancy; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D014157:Transcription Factors / Q000235:genetics; D015017:Yolk Sac / Q000166:cytology* / Q000378:metabolism
D018952:Antigens, CD34; D006133:Growth Substances; D012333:RNA, Messenger; D014157:Transcription Factors; D019009:Proto-Oncogene Proteins c-kit