Ovarian activity is differentially regulated across the breeding season in immature compared with adult American crows (Corvus brachyrhynchos)

Physiological and Biochemical Zoology : PBZ
Coventry O DoughertyKelly A Young

Abstract

American crow (Corvus brachyrhynchos) reproduction is seasonal. While photoperiod alters reproductive physiology and behavior in nesting adults, whether seasonal photoperiod changes alter ovarian activity in nonnesting adult and immature birds was not known. Ovarian follicular composition was examined in immature and nonnesting adult crows. Birds were divided into groups reflecting daylight hour exposure when captured: 12L, 12:30L, 13:30L, and 14L, representing early-, progressing-, peak-, and postbreeding seasons in southern California. Adult ovarian mass peaked in 13:30L and then decreased 65% by 14L. In contrast, immature ovarian mass peaked in 12L and decreased 58% by 14L. Whereas no change in adult follicle composition occurred, primordial follicle numbers increased 42%, and previtellogenic follicles increased 86% in immatures, resulting in an overall follicle number increase in immatures by 13:30L and 14L. Adult atretic follicles declined 68% by 14L, while immature atretic follicle numbers remained constant. Adult apoptotic transferase-mediated dUTP nick end labeling (TUNEL)-positive follicle numbers remained constant until a 52% decrease occurred in 13:30L. TUNEL-positive follicles declined 58% by 12:30L among immatures....Continue Reading

References

Jul 1, 1964·Journal of Theoretical Biology·W D Hamilton
Feb 13, 2001·Biology of Reproduction·K A YoungR J Nelson
Aug 17, 2001·Journal of Biological Rhythms·A DawsonG F Ball
Jul 19, 2002·Proceedings. Biological Sciences·A F Russell
Sep 27, 2002·Physiological and Biochemical Zoology : PBZ·François Vézina, Tony D Williams
Mar 12, 2004·Nature·Joshua JohnsonJonathan L Tilly
Jun 18, 2005·The Journal of Experimental Biology·François Vézina, Tony D Williams
Aug 19, 2008·The American Naturalist·Andrew D C MacColl, Ben J Hatchwell

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.