Characterization of different sizes of rat luteinizing hormone/chorionic gonadotropin receptor messenger ribonucleic acids

Expression of gonadotropin receptors and granulosa cell sensitivity to gonadotropin hormones by small (1-3 mm) and large (3.5-7 mm) follicles were compared in Romanov (ROM, ovulation rate = 3) and Ile-de-France (IF, ovulation rate = 1) ewes in the early and late follicular phase. In healthy follicles, LH receptor levels in granulosa cells increased with increasing follicular size (p < 0. 001) while FSH receptor levels decreased (p < 0.05). In granulosa cells of large follicles, LH receptor (LHR) mRNA levels were greater in the late than in the early follicular phase (p < 0.001, p < 0.05, for ROM and IF, respectively). In the early follicular phase, LHR levels in granulosa (p < 0.001) and theca cells (p < 0.05) of small follicles were greater in ROM than in IF ewes. FSH receptor mRNA levels in granulosa cells of small and large ROM follicles were greater than in the corresponding IF follicles (p < 0.05). Finally, a greater responsiveness (increase in cAMP secretion) to both FSH and hCG was observed by granulosa cells collected during the early follicular phase from ROM vs. IF ewes. Data provide evidence that the greater ovulation rate in the ROM as compared to the IF breed is associated with a greater gonadotropin responsiveness during the early follicular phase.

Section: Discussionsupporting

confidence: 56%

Comparative Expression of Luteinizing Hormone and Follicle-Stimulating Hormone Receptors in Ovarian Follicles from High and Low Prolific Sheep Breeds1

Abdennebi¹,

Monget²,

Pisselet³

et al. 1999

“…In several species, the LHR gene is alternatively spliced during transcription, either by exon skipping or by use of alternative splice sites, resulting in a number of potential LHR isoforms [9][10][11][12][13][14]. Nearly all the described LHR isoforms remain untranslated, or, if translated, they cannot be properly transported to the cell membrane and remain trapped inside the cytoplasm.…”

Section: Introductionmentioning

confidence: 99%

A New Subclass of the Luteinizing Hormone/Chorionic Gonadotropin Receptor Lacking Exon 10 Messenger RNA in the New World Monkey (Platyrrhini) Lineage1

Gromoll

Wistuba

Terwort

et al. 2003

The luteinizing hormone receptor (LHR) plays an essential role as a mediator of LH and CG action during embryonic sexual differentiation and in gametogenesis. In a hypogonadal male patient, we recently demonstrated that a genomic deletion of exon 10, located in the hinge region of the extracellular domain, results in discrimination of LH and hCG action. In the common marmoset (Calltithrix jacchus), exon 10 of the LHR is naturally missing at the mRNA level. In order to investigate whether this is an isolated species-specific phenomenon, we performed a phylogenetic screening, searching for the presence of LHR exon 10 mRNA in a number of primate species representative for the major lineages of primate evolution. The expressed LHR region encompassing exon 10 was amplified from testicular tissue by RT-PCR, cloned, and sequenced. In addition, we performed Southern blot analysis of the LHR of selected New World and Old World primates. The results revealed that exon 10 mRNA is lacking in the complete New World monkey (Platyrrhini) lineage but is present in both more primitive and more advanced primates. However, exon 10 seems to be present at the genomic level, arguing for a splicing failure possibly due to a genomic mutation or the lack of appropriate splicing factors. Considering that, in the human, LH is far less active than hCG on the LHR lacking exon 10, we addressed the question whether the existence of such a receptor has any consequences on the dual hormone LH/CG system present in Platyrrhini. Using primers specific for the known marmoset CG beta cDNA, we amplified the CG beta subunit cDNA from male common marmoset pituitaries by RT-PCR, while LH beta could not be amplified, suggesting a possible physiological role of pituitary CG in this species. In conclusion, we demonstrated for the first time that the LH mRNA without exon10 is the natural wild-type LHR in the Platyrrhini lineage. We propose that this LHR represents a new subclass of receptors that should be named LHR type II. In addition, the high expression of CG beta in the marmoset pituitary suggests a physiological role of CG in the reproductive function of these primates beyond pregnancy.

“…FAX: 0044 141 330 5797; e-mail: gvyaO9@udcf.gla.ac.uk ceptor have been described in the mouse [15]. The structure of alternate transcripts of the LH receptor in the mouse ovary are unknown, but more than 18 different transcripts have been found in the rat [16,17].…”

Section: Introductionmentioning

confidence: 99%

Regulation of Luteinizing Hormone-Receptor and Follicle-Stimulating Hormone- Receptor Messenger Ribonucleic Acid Levels during Development in the Neonatal Mouse Ovary1

O’Shaughnessy

McLelland

McBride

1997

Normal gonadal development is dependent upon stimulation by the gonadotropic hormones, and it is likely that control of ovarian development is regulated by expression of gonadotropin receptors. In this study, quantitative changes in LH- and FSH-receptor mRNA levels were measured in the ovary during development in normal mice and in hypogonadal (hpg/hpg) mice, which lack circulating gonadotropins. The relative abundance of alternate transcripts encoding LH and FSH receptors was also determined. Results show that shortened transcripts of the receptors were abundant at all ages. Full-length transcripts of the LH receptor were not detectable until postnatal Day 5 although shortened transcripts encoding the extracellular domain of the receptor were present from birth. Between Days 5 and 7, LH-receptor transcript levels showed a marked increase in normal animals but no change in hpg/hpg animals. FSH-receptor transcripts encoding all domains of the receptor were detectable at low levels at birth, increased in concentration between Days 3 and 5, and peaked at Day 10. In hpg/hpg animals, FSH-receptor mRNA levels were normal up to Day 7 but failed to increase thereafter. These results show that early development of both LH- and FSH-receptor mRNA levels in the ovary is gonadotropin-independent. This coincides with early folliculogenesis to the primary stage. Further development of LH-receptor mRNA levels is gonadotropin-dependent although FSH-receptor mRNA levels continue to increase independently until early secondary follicles are present.