Successful artificial insemination in the Asian elephant (Elephas maximus) using chilled and frozen-thawed semen

<p>Abstract</p> <p>Background</p> <p>Artificial insemination (AI) using frozen-thawed semen is well established and routinely used for breeding in various mammalian species. However, there is no report of the birth of elephant calves following AI with frozen-thawed semen. The objective of the present study was to investigate the fertilizing ability of chilled and frozen-thawed semen in the Asian elephant following artificial insemination (AI).</p> <p>Methods</p> <p>Semen samples were collected by from 8 bulls (age range, 12-to 42-years) by manual stimulation. Semen with high quality were either cooled to 4°C or frozen in liquid nitrogen (-196°C) before being used for AI. Blood samples collected from ten elephant females (age range, 12-to 52-years) were assessed for estrus cycle and elephants with normal cycling were used for AI. Artificial insemination series were conducted during 2003 to 2008; 55 and 2 AI trials were conducted using frozen-thawed and chilled semen, respectively. Pregnancy was detected using transrectal ultrasonography and serum progestagen measurement.</p> <p>Results</p> <p>One female (Khod) inseminated with chilled semen became pregnant and gave birth in 2007. The gestation length was 663 days and the sex of the elephant calf was male. One female (Sao) inseminated with frozen-thawed semen showed signs of pregnancy by increasing progestagen levels and a fetus was observed for 5 months by transrectal ultrasonography.</p> <p>Conclusion</p> <p>This is the first report showing pregnancy following AI with frozen-thawed semen in the Asian elephant. Successful AI in the Asian elephant using either chilled or frozen-thawed semen is a stepping stone towards applying this technology for genetic improvement of the elephant population.</p

Mating changes the subcellular distribution and the functionality of estrogen receptors in the rat oviduct

Background: Mating changes the mode of action of 17beta-estradiol (E2) to accelerate oviductal egg transport from a nongenomic to a genomic mode, although in both pathways estrogen receptors (ER) are required. This change was designated as intracellular path shifting (IPS). Methods: Herein, we examined the subcellular distribution of ESR1 and ESR2 (formerly known as ER-alpha and ER-beta) in oviductal epithelial cells of rats on day 1 of cycle (C1) or pregnancy (P1) using immunoelectron microscopy for ESR1 and ESR2. The effect of mating on intraoviductal ESR1 or ESR2 signaling was then explored comparing the expression of E2-target genes c-fos, brain creatine kinase (Ckb) and calbindin 9 kDa (s100g) in rats on C1 or P1 treated with selective agonists for ESR1 (PPT) or ESR2 (DPN). The effect of ER agonists on egg transport was also evaluated on C1 or P1 rats. Results: Receptor immunoreactivity was associated with the nucleus, cytoplasm and plasma membrane of the epithelial cells. Matin

Influences of Domestication and Island Evolution on Dental Growth in Sheep

Abstract: Domestication and island evolution can lead to changes of life history along the slow-fast gradient. Shifts of life history patterns, in turn, are potentially related to alterations of patterns and timing of tooth eruption. Schultz’s rule predicts an earlier eruption of molars relative to premolars as fecundity increases during the domestication process. On the other hand, evolution on a predator-free, resource limited island might lead to a generally slow life history and delayed tooth eruption, as in the Plio-Pleistocene Balearic caprine Myotragus. In this study, we investigate tooth eruption and its relation to life history in a unique sheep population that is an example of both domestication and island evolution: the ancient and feral Soay sheep (Ovis aries) of the St. Kilda archipelago, Scotland. Tooth eruption timing and sequence is investigated in a comparative framework featuring new data on other domestic sheep (O. aries), including European mouflon (O. a. musimon), as well as wild sheep (O. vignei, O. cycloceros, O. arkal, O. orientalis, O. ammon). These data indicate that the order of eruption is similar in wild and domestic sheep, despite the fundamental life history changes that came about with domestication. However, in contrast to other domestic sheep breeds, Soay sheep erupt their teeth at an absolute older age and also tend to grow more slowly, which resembles the evolutionary trend in island-adapted Myotragus. Despite these similarities, Soay sheep do not share the slow life history pattern inferred for Myotragus, highlighting the distinctive nature of tooth eruption in Soay sheep

Morphology of the Uterotubal Junction of the Cheetah ( Acinonyx jubatus

Less than 7,000 cheetahs survive in the wild. Captive breeding has proved notoriously difficult. The uterotubal junction acts as major barrier and regulator to the passage of sperm. This study describes the morphology of the uterotubal junction of the cheetah. Reproductive tracts were obtained from seven cheetahs that succumbed from natural causes or were euthanized for humane reasons. The uterotubal junction was isolated and examined macroscopically and microscopically. The extramural isthmus made a characteristic 90° bend before entering the mesometrial border of the uterus close to its tip. The intramural isthmus had approximately four primary folds lined by nonciliated cuboidal to low cuboidal epithelium. The Tunica muscularis was robust, merged with its uterine counterparts and consisted of an inner circular layer and outer longitudinal smooth muscle layer. The uterine ostium opened via a muscular and glandular papilla that projected from the apex of the uterine lumen. A sharply demarcated circular zone of simple columnar epithelial cells surrounded the uterine ostium and separated the simple cuboidal to low cuboidal cells of the isthmus and uterine epithelium from each other. Branched tubulo‐alveolar glands, some with dilated lumens, were present in the papilla and sometimes extended into the adjacent endometrium. These glands might act as sperm storage areas, and could easily be confused with cystic endometrial hyperplasia. Low transverse endometrial ridges surrounded the papilla and extended caudally for a short distance before disappearing. The uterine glands were lined by a simple cuboidal epithelium.The University of Pretoriahttps://onlinelibrary.wiley.com/journal/193284942020-10-01hj2019Anatomy and PhysiologyCompanion Animal Clinical Studie