Stereological analysis of the naked mole-rat lung provides evidence of altered surfactant function and late alveolarization.

Naked-mole rats (NMRs; ) exhibit unique biological traits such as resistance to cancer, exceptional longevity, and high tolerance to low-oxygen environments. However, little is known about the lung structure of this eusocial species. Here, the lungs of adult NMRs were qualitatively examined using light and electron microscopy, followed by structural quantification of the alveolar region by means of stereology.

Advanced assisted reproduction technologies in endangered mammalian species.

A new synergistic approach of classical conservation strategies combined with advanced assisted reproduction technologies (aART) allows for protection and rescue of endangered keystone species at the brink of extinction, which can help to safeguard complex ecosystems. Reproduction biology and management in mammal species is not only challenging in regards to their diverging sizes, anatomy, and often unknown physiology; it also requires customized training or chemical restraint protocols for safe handling. Besides these general challenges, there are several new assisted reproduction techniques (ART) specifically tailored to critically endangered mammals.

The neonatal southern white rhinoceros ovary contains oogonia in germ cell nests.

The northern white rhinoceros is functionally extinct with only two females left. Establishing methods to culture ovarian tissues, follicles, and oocytes to generate eggs will support conservation efforts using in vitro embryo production. To the best of our knowledge, this is the first description of the structure and molecular signature of any rhinoceros, more specifically, we describe the neonatal and adult southern white rhinoceros (Ceratotherium simum simum) ovary; the closest relation of the northern white rhinoceros.

Abundance and size of hyaluronan in naked mole-rat tissues and plasma.

Large amounts of ultra-high molecular weight hyaluronan (HA) have been described as the main cause of cancer resistance in naked mole-rats (Heterocephalus glaber, NMR). Our work examined HA metabolism in these rodents more closely. HA was localized and quantified using HA binding proteins.

Telomeres and Longevity: A Cause or an Effect?

Telomere dynamics have been found to be better predictors of survival and mortality than chronological age. Telomeres, the caps that protect the end of linear chromosomes, are known to shorten with age, inducing cell senescence and aging. Furthermore, differences in age-related telomere attrition were established between short-lived and long-lived organisms.

Cryopreservation in rhinoceros-Setting a new benchmark for sperm cryosurvival.

At times when rhinoceros are fiercely poached, when some rhinoceros species are closer than ever to extinction, and when the scientific community is in debate over the use of advanced cell technologies as a remaining resort it is time to simplify and improve existing assisted reproduction techniques to enhance breeding and genetic diversity in the living populations under our care. Semen cryopreservation has been performed in all captive rhinoceros species with limited degree of success. Here we tested three freezing extenders, containing different cryoprotectants and various freezing rates for the cryopreservation of rhinoceros sperm from 14 bulls.

Unraveling the gut microbiome of the long-lived naked mole-rat.

The naked mole-rat (Heterocephalus glaber) is a subterranean mouse-sized African mammal that shows astonishingly few age-related degenerative changes and seems to not be affected by cancer. These features make this wild rodent an excellent model to study the biology of healthy aging and longevity. Here we characterize for the first time the intestinal microbial ecosystem of the naked mole-rat in comparison to humans and other mammals, highlighting peculiarities related to the specific living environment, such as the enrichment in bacteria able to utilize soil sulfate as a terminal electron acceptor to sustain an anaerobic oxidative metabolism.

Monitoring health and reproductive status of olms (Proteus anguinus) by ultrasound.

The olm (Proteus anguinus) is a troglomorphic, neotenous amphibian with extraordinary life expectancy and unique adaptations that deserve further investigation. A low reproductive rate and habitat decline render it threatened by extinction. Establishing captive populations for maintenance and artificial breeding may one day become crucial to the species.

Follicular size predicts success in artificial insemination with frozen-thawed sperm in donkeys.

In asses, semen collection, cryopreservation, and artificial insemination (AI) with frozen-thawed semen have been scarcely described and success rate, particularly following AI, is reportedly low. In the absence of reliable protocols, assisted reproductive technologies cannot support the conservation efforts aimed at endangered wild ass species and domestic donkey breeds. Two experiments were conducted in this study.

Ovarian down Regulation by GnRF Vaccination Decreases Reproductive Tract Tumour Size in Female White and Greater One-Horned Rhinoceroses.

Reproductive tract tumours, specifically leiomyoma, are commonly found in female rhinoceroses. Similar to humans, tumour growth in rhinoceroses is thought to be sex hormone dependent. Tumours can form and expand from the onset of ovarian activity at puberty until the cessation of sex-steroid influences at senescence.

Analysis of cultivable microbiota and diet intake pattern of the long-lived naked mole-rat.

Background: A variety of microbial communities exist throughout the human and animal body. Genetics, environmental factors and long-term dietary habit contribute to shaping the composition of the gut microbiota. For this reason the study of the gut microbiota of a mammal exhibiting an extraordinary life span is of great importance.

Controlled ice nucleation--Is it really needed for large-volume sperm cryopreservation?

Controlled ice nucleation (CIN) is an integral stage of slow freezing process when relatively large volumes (usually 1 mL or larger) of biological samples in suspension are involved. Without it, a sample will supercool to way below its melting point before ice crystals start forming, resulting in multiple damaging processes. In this study, we tested the hypothesis that when freezing large volumes by the directional freezing technique, a CIN stage is not needed.

CRYOPRESERVATION OF ONAGER (EQUUS HEMIONUS ONAGER) EPIDIDYMAL SPERMATOZOA.

Genetic diversity is a primary component of adaptive evolution, and its loss or reduction can decrease the long-term survival probability of populations. Utilization of cryopreserved semen may be considered a perfect tool to improve genetic diversity, reduce inbreeding, and avoid animal translocation for breeding. The present study aimed at finding a reliable epididymal sperm freezing protocol for the critically endangered onager (Equus hemionus onager).

Supression of testicular function in a male Asian elephant (Elephas maximus) treated with gonadotropin-releasing hormone vaccines.

The ability to control testosterone concentrations and sperm production is of great interest in both Asian (Elephas maximus) and African (Loxodonta africana) elephants. GnRH vaccination may pose an alternative to surgical castration. This is a case report of a male Asian elephant treated with two commercial GnRH vaccines (Equity and Improvac).

Rhinoceros feet step out of a rule-of-thumb: a wildlife imaging pioneering approach of synchronized computed tomography-digital radiography.

Currently, radiography is the only imaging technique used to diagnose bone pathology in wild animals situated under "field conditions". Nevertheless, while chronic foot disease in captive mega-herbivores is widely reported, foot radiographic imaging is confronted with scarcity of studies. Numerous hindrances lead to such limited numbers and it became very clear that the traditional perspective on bone imaging in domestic animals based on extensive studies and elaborated statistical evaluations cannot be extrapolated to their non-domestic relatives.

Free blastocyst and implantation stages in the European brown hare: correlation between ultrasound and histological data.

The European brown hare (Lepus europaeus) is the only species with superconception, whereby the maternal reproductive tract hosts two sets of conceptuses at different developmental stages. The embryonic development of the hare has not yet been described. To understand the mechanism of superconception, we studied oviduct transport and implantation stages by embryo flushing and live high-resolution ultrasound.

The long gestation of the small naked mole-rat (Heterocephalus glaber Rüppell, 1842) studied with ultrasound biomicroscopy and 3D-ultrasonography.

The naked mole-rat (Heterocephalus glaber) is one of the two known mammalian species that live in a eusocial population structure. Here we investigate the exceptionally long gestation period of 70 days observed in the mole-rat queen. The course of seven successful pregnancies in two individuals was recorded in a colony of captive naked mole-rats using ultrasound biomicroscopy (UBM) and 3D-ultrasonography.

Sonomorphology of the reproductive tract in male and pregnant and non-pregnant female Rothschild's giraffes (Giraffa camelopardalis rotschildi).

The application of real-time-B-mode ultrasonography to wild and zoo animal medicine has been shown to improve the understanding of reproductive physiology in many species. Ultrasound technology is especially helpful for monitoring urogenital health, which in turn has advantages for giraffe breeding and welfare in captivity. This study aimed to ultrasonographically describe the genital organs of reproductively healthy male and female giraffes.

High-resolution ultrasonography of xenografted domestic cat ovarian cortex.

Transplantation of ovarian tissue has high potential for female gamete conservation. However, optimal timing of oocyte recovery for in vitro maturation and fertilization is still critical. Therefore the aim of the present study was to use high-resolution transcutaneous ultrasonography to monitor follicular development within xenografted ovarian tissue.

The effect of long non-reproductive periods on the genital health in captive female white rhinoceroses (Ceratotherium simum simum, C.s. cottoni).

White rhinoceroses suffer from a low reproductive rate in captivity. Intensive efforts to propagate specifically the northern white rhinoceros have been very limited. The dismal outlook for this subspecies in the wild makes successful ex situ breeding programs paramount.

Reproductive soundness of captive southern and northern white rhinoceroses (Ceratotherium simum simum, C.s. cottoni): evaluation of male genital tract morphology and semen quality before and after cryopreservation.

White rhinoceroses suffer from a low rate of reproduction in captivity. This study examines the role of male reproductive function as a contributing factor. We used ultrasonography to image accessory sex glands, testis and epididymis.