Animal Reproductive Biology Group

Michael Roberts

Curators' Professor
Animal Sciences/Biochemistry

Phone: 573-882-7957
E-mail: RobertsrM@missouri.edu
Address: 240b Life Sciences Center

Education

B.A., Oxford University
Ph.D., Oxford University
Postdoc, State University of New York

Research Focus

Conceptus and interferon-t
Early gene expression in the conceptus
Gene expression in the placenta
Effect of diet on sex of offspring

Research Description

Maternal-conceptus interactions during early pregnancy in cattle.

Research in the Roberts laboratory is in several areas, mainly relating to trophoblast (placental) function and differentiation. A primary focus is on the interferon-tau, a family of gene products that were first cloned and identified in this laboratory as products of trophectoderm or pecoran ruminants, such as cattle and sheep, prior to attachment of the trophoblast to the uterine wall. The role of the interferon-tau is in maternal recognition of pregnancy and particularly in preventing the regression of the corpus luteum and loss of progesterone support of early pregnancy. Present interests center around the transcriptional control of the several interferon-tau genes, the signaling function of the interferon receptor in the endometrium and the downstream genes that are regulated by IFN-t in the maternal uterus. The potential use of pharmacologically administered IFN-t in improving pregnancy success in cattle is also being studied.

A second project is on the role of transcription factors that are required for specification of the cell lineage that leads to the formation of trophoblast and that also seem to be necessary to drive the expression of the signature genes characteristic of trophoblast. Among the candidates being studied are Ets2, Dlx3, and Cdx2. The latter is particularly intriguing because it appears to be involved in pre-patterning of mouse embryonic development as early as the mature oocyte. Consequently, expression of the Cdx2 gene can be used to identify which cells of the cleavage stage embryo are destined to form trophoblast.

A third interest is in the control of differentiation of human embryonic stem cells. The laboratory is particularly interested in the manner whereby differentiation of human ES cells can be largely eliminated by maintaining the cells under hypoxic conditions, even though growth of the cells is not compromised by low oxygen. This discovery allows investigators to grow these cell lines without the concern that they are undergoing spontaneous differentiation. It will also allow the phenotype of the undifferentiated ES cell to be defined.

A fourth interest is on how maternal diet can influence the sex of her offspring. Using a mouse model, the Roberts laboratory has shown that diets high in fat tend to skew the sex ratio of pups towards males, whereas a low-fat diet favors female pups. This bias is unrelated to the weight of the mothers. Present research is focused on the mechanisms involved in causing sex ratio skewing.

Recent Publications

Green MP, Spate LD, Bixby JA, Ealy AD, Roberts RM.
A Comparison of the Anti-Luteolytic Activities of Recombinant Ovine Interferon-Alpha and -Tau in Sheep. Biol Reprod. 2005 Aug 3; [Epub ahead of print] PMID: 16079305
Kimura K, Spate LD, Green MP, Roberts RM.
Effects of D-glucose concentration, D-fructose, and inhibitors of enzymes of the pentose phosphate pathway on the development and sex ratio of bovine blastocysts. Mol Reprod Dev. 2005 Oct;72(2):201-7. PMID: 15968626
Roberts RM.
Embryo culture conditions: what embryos like best. Endocrinology. 2005 May;146(5):2140-1. No abstract available. PMID: 15833923
Ezashi T, Das P, Roberts RM.
Low O2 tensions and the prevention of differentiation of hES cells. Proc Natl Acad Sci U S A. 2005 Mar 29;102(13):4783-8. Epub 2005 Mar 16. PMID: 15772165
Green JA, Parks TE, Avalle MP, Telugu BP, McLain AL, Peterson AJ, McMillan W, Mathialagan N, Hook RR, Xie S, Roberts RM.
The establishment of an ELISA for the detection of pregnancy-associated glycoproteins (PAGs) in the serum of pregnant cows and heifers. Theriogenology. 2005 Mar 15;63(5):1481-503. PMID: 15725453
Wang SZ, Roberts RM.
The evolution of the Sin1 gene product, a little known protein implicated in stress responses and type I interferon signaling in vertebrates. BMC Evol Biol. 2005 Feb 7;5(1):13. PMID: 15698473
Ghosh D, Sachdev S, Hannink M, Roberts RM.
Coordinate regulation of basal and cyclic 5'-adenosine monophosphate (cAMP)-activated expression of human chorionic gonadotropin-alpha by Ets-2 and cAMP-responsive element binding protein. Mol Endocrinol. 2005 Apr;19(4):1049-66. Epub 2005 Jan 6. PMID: 15637148
Wang SZ, Roberts RM.
Interaction of stress-activated protein kinase-interacting protein-1 with the interferon receptor subunit IFNAR2 in uterine endometrium. Endocrinology. 2004 Dec;145(12):5820-31. Epub 2004 Sep 2. PMID: 15345682
Roberts RM, Ezashi T, Das P.
Trophoblast gene expression: transcription factors in the specification of early trophoblast. Reprod Biol Endocrinol. 2004 Jul 5;2:47. Review. PMID: 15236655
A complete list of publications for RM Roberts in PubMed