Rabbit oocyte can be used as the recipient in interspecies somatic cell nuclear transfer (iSCNT). This work was undertaken in order to study the developmental competence of Capra ibex somatic cells reprogrammed by rabbit oocytes and the fate of mitochondria in iSCNT embryos. Metaphase II (MII) oocytes from superovulated rabbit were used as nuclear recipients. The nuclear donors were Capra ibex somatic cells with different proliferative status: population doubling time (PDL)=15±2 (group 1), 35±2 (group 2), 55±2 (group 3) and 70±2 (group 4). Oocytes reconstructed with electrical pulses (2.1 kV/cm, 10 μs, 2 times) were activated (1.4 kV, 20 μs, 2 times) and then cultured in Medium199 containing 10% fetal bovine serum at 38.5 °C, 5% CO2 in air. In groups 1, 2, 3 and 4, the fusion rates were 35.83%, 66.03%, 65.40% and 35.35%, respectively. Similar cleavage rates were observed among the four groups. However, the developmental potential to morula/blastocyst from early nuclear donor embryos (16.42%/10.45%) was significantly higher (p < 0.05) than in terminal donor embryos (9.52%/3.81%). Polymerase chain reaction analysis of the mitochondrial (mt) DNA cytb gene demonstrated that mtDNAs from ibex and rabbit could be detected at various developmental stages before implantation. In conclusion, our results provide some original information about rescuing Capra ibex using the iSCNT technique. These results indicate that: (1) enucleated rabbit oocytes make Capra ibex fibroblast nuclei reprogramme; (2) the proliferative status of donor cells affects the efficiency of iSCNT; and (3) rabbit ooplasm rescues the donor-derived mtDNAs, resulting in mtDNA heteroplasmy before implantation.

Senescence can be defined as accelerating phenotypic deterioration with old age. For traits that grow throughout life, such as the horns of some ungulates, senescence may be expressed as a decrease in annual growth rates, or an increase in asymmetry, in the years preceding death. Age-specific yearly horn-growth segments of 378 male Alpine ibex Capra ibex L. that died from natural causes were analysed in the Gran Paradiso National Park (Italian Alps). Horn annuli displayed fluctuating asymmetry. The hypothesis that asymmetry and size of the annuli of the horns could predict annual survival probability was tested. It was found that between 5 and 11 years of age, male ibex that grew shorter annuli than the average for the population had a greater probability of mortality over the following years than those with greater rates of horn growth. Horn asymmetry and mortality rates were not significantly correlated. Annulus size, reflecting the onset of senescence, seemed to be a better indicator of individual quality than annulus asymmetry.

Rates of increase, survival and reproduction were studied in two re-introduced populations of mountain ungulates, the Pyrenean chamois (also named isard, Rupicapra pyrenaica) and the ibex (Capra ibex) in the French Alps. The populations were monitored from 1983 to 1998 (ibex) or 1984 to 1999 (isard) using capture, marking and resighting of individuals. Population rates of increase were estimated during the colonizing phase from: (1) a time series of estimates of population size; (2) projection matrices based on rates of survival and fecundity. Both populations had exponential rates of increase, with annual multiplication rates of 1.28 for isard and 1.30 for ibex. Age of first reproduction was 2 years in both species, with 77% of females breeding at this age in isard and 43% in ibex. From 3 years of age onwards, 90% of isard and 87% of ibex females bred each year. Survival rates of adult females, estimated using capture–recapture models, equalled 0.94 for isard and 0.98 for ibex, whatever the age and year. The projection matrix led to a slightly lower asymptotic multiplication rate than the time series of population size. Despite adult body size of the ibex being about twice that of the isard, no difference was detected in the intrinsic rate of increase between the two species. This supported the hypotheses of homogeneous life-history traits among ungulates, varying little with body size.