N. Kawate et K. Okuda, COORDINATED EXPRESSION OF SPLICE VARIANTS FOR LUTEINIZING-HORMONE RECEPTOR MESSENGER-RNA DURING THE DEVELOPMENT OF BOVINE CORPORA-LUTEA, Molecular reproduction and development, 51(1), 1998, pp. 66-75
We characterized splice variants for LH receptor mRNA in the bovine co
rpus luteum and examined the levels of expression of all the splice va
riants during the development of corpus luteum. Total RNA was extracte
d from bovine corpora lutea, and reverse transcriptase-polymerase chai
n reaction (RT-PCR] was performed to amplify a part of the extracellul
ar and transmembrane domains. As a result, four distinct bands were ob
served on analyses with polyacrylamide gel electrophoresis, and sequen
cing of the products revealed that the largest form (519 bp) was the f
ull-length A form and that the three shorter forms [438, 253, and 172
bp) were its splicing variants. Splicing patterns of the 438-, 253-, a
nd 172-bp forms are identical to the F, B, and G forms, respectively,
found in the ovine ovary. In order to examine the level of expression
of all these splice variants simultaneously, semiquantitative RT-PCR w
as set up and performed. The relative intensities for all four forms o
f LH receptor mRNA significantly increased (P < 0.05) from Stage I (Da
ys 1-4; Day 1 = day of ovulation) to IIS (Days 5-10, CL weight < 4 g),
and from Stage IIS to IIL (Days 5-10, CL weight greater than or equal
to 4 g). The intensities of all forms for LH receptor mRNA decreased
slightly, but not significantly, from Stage IIL to III (Days 11-17). T
he ratios of the levels for all the forms did not change significantly
during the development of the corpus luteum. Determination of the ste
ady-state levels of LH receptor mRNA by Northern blotting showed simil
ar changes during the development of the corpus luteum to changes of t
he splice variants examined by the semiquantitative RT-PCR. These resu
lts suggest that at least three splicing variants of LH receptor mRNA
(i.e., F, B, and G forms) exist in the bovine corpus luteum and that t
he levels of all the forms of LH receptor mRNA increased in a coordina
ted manner during the development of bovine corpus luteum. Mel. Reprod
. Dev. 51:66-75, 1998. (C) 1998 Wiley-Liss, Inc.