Related Experiment Video
Updated: Apr 11, 2026
07:03
A Modified Co-Culture System for Understanding Granulosa-Theca Cell Interactions in the Bovine Ovary
Published on: September 19, 2025
761
A Major Gene for Bovine Ovulation Rate
Brian W Kirkpatrick1, Chris A Morris2
1Department of Animal Sciences, University of Wisconsin-Madison, Madison, WI, United States of America.
Plos One
|June 6, 2015
Summary
Researchers identified a major gene influencing ovulation rate in cattle, localized to chromosome 10. This discovery aids in tracking high ovulation rate alleles in cattle breeding.
Area of Science:
- Animal Genetics
- Reproductive Biology
- Quantitative Genetics
Background:
- A major gene is suspected to control high ovulation rates in cattle.
- Understanding the genetic basis of ovulation rate is crucial for livestock breeding.
Purpose of the Study:
- To test the hypothesis of a major gene for high ovulation rate segregation.
- To map the location of this major gene in cattle.
Main Methods:
- Genotyping of 131 half-sib daughters and their sire using SNP chips (3K, 50K, 777K).
- Phenotypic evaluation of ovulation rate via transrectal ultrasonography over four estrous cycles.
- Linkage analysis and fine-mapping to a 1.2 Mb region on bovine chromosome 10.
- Candidate gene analysis (SMAD3, SMAD6, IQCH) within the mapped region.
Main Results:
- Strong evidence (p < 1 x 10(-28)) for a major gene controlling ovulation rate.
- Gene localized to bovine chromosome 10, specifically between 13.6 and 14.8 Mb.
- The identified region does not overlap with previously known ovulation rate genes.
- Three polymorphisms identified for haplotype-based tracking of the high ovulation rate allele.
Conclusions:
- A novel major gene significantly impacts ovulation rate in cattle.
- The gene is located on chromosome 10, providing a target for further research.
- Developed polymorphisms can facilitate marker-assisted selection for improved fertility.
Related Concept Videos
01:27Ovarian Cycle
5.6K
The menstrual cycle includes a critical component known as the ovarian cycle, which undergoes two main phases each month—the follicular phase and the luteal phase. The follicular phase is variable and averaging around 14 days. Ovulation, triggered by a surge in luteinizing hormone (LH), marks the transition between the two phases. The second phase, the luteal phase, is relatively consistent, lasting approximately 14 days, and is marked by the activity of the corpus luteum. While a cycle...
5.6K
01:30Hormonal Control of the Ovarian Cycle
7.8K
The ovarian cycle is meticulously regulated by the hypothalamic-pituitary-gonadal axis. This cycle orchestrates the release of a mature oocyte, essential for reproduction.
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
7.8K
02:07Oogenesis
71.5K
In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...
71.5K
01:22Oogenesis
5.2K
Oogenesis, the process of developing egg cells (female gametes), occurs within the ovaries and is fundamental to female fertility. This sequence begins during fetal development when diploid oogonia in the developing ovaries undergo mitotic divisions to produce primary oocytes. By birth, these primary oocytes enter prophase I of meiosis but become arrested in this stage, remaining suspended until puberty.
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is...
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is...
5.2K
01:26Ovaries
3.5K
The ovaries are roughly the size of almonds and measure approximately 2 to 3 centimeters in length. These paired structures are situated within the pelvic region and are anchored by the mesovarium—a peritoneal extension that also connects them to the wider structure of the broad ligament. The support system extends to the suspensory ligament, housing blood and lymphatic vessels. In addition, the ovarian ligament tethers the ovaries to the uterus.
On the ovarian surface, a layer of...
On the ovarian surface, a layer of...
3.5K
01:24Gonadal and Placental Hormones
4.2K
The gonads, namely the testes in males and the ovaries in females, are pivotal in producing gonadal hormones that orchestrate the intricate processes of sexual development and reproduction.
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair...
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair...
4.2K