Aleksandar Rajkovic M.D., Ph.D.
Department Obstetrics & Gynecology - Reproductive Genetics
6550 Fannin Suite 901
Houston, TX 77030
Telephone: 713-798-7500 (appointment)
Telephone: 713-798-8360 (office)
The Johns Hopkins University, B.S.
Case Western University School of Medicine, M.D./Ph.D.
Residency Obstetrics and Gynecology, Cleveland Metropolitan General Hospital
and Cleveland Clinic Foundation, Cleveland, Ohio
Fellowship Human Genetics, Baylor College of Medicine, Houston, Texas
Our interests lie in basic sciences and translational research in the area of reproductive genetics. We are specifically interested in studying transcriptional regulation of mammalian oogenesis and identifying biomarkers for placental disorders, and reproductive tissue cancers.
Oocyte is one of the rarest and largest cell in the body. Oocytes are essential for fertility, embryogenesis and are capable of reprogramming nuclei. Defects in oocyte gene expression can lead to premature ovarian failure, infertility, ovarian tumors, and early embryo losses. In addition, proteins specifically produced in the oocytes can be useful targets for pharmaceuticals to regulate human fertility. We are interested in understanding what makes oocyte such a unique cell, and identify transcriptional cascade that enables the oocyte to increase in size almost 300 fold as it grows from the primordial oocyte to mature egg ready for fertilization. We have discovered a number of oocyte-specific genes that play crucial functions in oogenesis. We have focused our attention on several oocyte-specific transcription factors with homeodomain and helix-loop-helix domains that play critical functions in early mammalian oogenesis. Mice that lack these transcription factors are essential tools to understand in vivo how these oocyte-specific transcription factors affect ovarian physiology and which genes are regulated and regulate expression of these oocyte-specific transcription factors. These studies will be important in understanding oocyte-specific transcription pathways and will ultimately enable us to generate oocytes from somatic cells.
We are also using genomic analysis and tools to identify biomarkers predictive of adverse pregnancy outcomes. Our approach is to identify genes that are exclusively or preferentially expressed in placenta and study whether changes in protein levels produced by such genes predict preeclampsia, trisomies and other adverse outcomes in pregnancy. We are using similar approaches in ovarian cancer. Such biomarkers may also provide a target for therapy in the future.
Qin Y, Choi Y, Zhao H, Simpson J.L., Chen Z, Rajkovic A (2007) Nobox homeobox mutation causes premature ovarian failure, Am J Hum Genet., Sep;81(3):576-81
Choi Y, Qin Y, Berger MF, Ballow DJ, Bulyk ML, Rajkovic A. (2007) Microarray Analyses of Newborn Mouse Ovaries Lacking Nobox. Biol Reprod. Aug;77(2):312-9
Qin Y, Zhao H, Kovanci E, Simpson J.L., Chen Z, Rajkovic A (2007) Mutation Analysis of NANOS3 in 80 Chinese and 88 Caucasian Women with Premature Ovarian Failure, Fertil. Steril. Nov;88(5):1465-7
Choi Y, Rajkovic A. (2006) Characterization of NOBOX DNA binding specificity and its regulation of Gdf9 and Pou5f1 promoters. J Biol Chem. 2006 Nov 24;281(47):35747-56
Ballow DJ, Xin Y, Choi Y, Pangas SA, Rajkovic A. (2006) Sohlh2 is a germ cell-specific bHLH transcription factor. Gene Expr Patterns. Oct;6(8):1014-8.
Pangas, S., Choi, Y., Ballow, D., Zhao Y., Westphal, H., Matzuk, M., Rajkovic, A. (2006) Oogenesis requires germ cell specific transcriptional regulators Sohlh1 and Lhx8, Proc. Natl. Acad. Sci. U.S.A, May 23;103(21):8090-5
Ballow, D., Meistrich, M., Matzuk, M., Rajkovic, A., (2006) Sohlh1 is essential in spermatogonial differentiation. Developmental Biology, June 1;294(1):161-7
Choi, Y., and Rajkovic, A., (2006) Genetics of early folliculogenesis. Cellular and Molecular Life Sciences, Mar;63(5):579-90
Pangas, S.A., and Rajkovic, A. (2006) Transcriptional regulation of early oogenesis: In search of Masters., Human Reproduction Update, Jan-Feb;12(1):65-76
Rajkovic A., Pangas, S.A., Ballow, D., Suzumori, N., Matzuk M.M. (2004) Nobox regulates oocyte-specific gene expression in early folliculogenesis, Science, 305, 1157-1159