Abstract: If, in a mix-up at a costume shop, a couple were issued the front half of a zebra suit and the back half of a horse, it could be considered a quagga disguise. But if the masqueraders were pressed as to whether they were more horse or more zebra, the latest biochemical research advises them to insist on zebra.
The quagga, a South African animal extinct for more than 100 years, has been a source of confusion among taxonomists. Some contend, on the basis of the quagga skins preserved in museums, that this front-striped animal is a zebra, either a fourth zebra species or a variant of the Plains zebra, whose hindquarter stripes are dim. But others have argued that the quagga's teeth and skeleton indicate that its nearest relative is the true horse.
Biochemists joined the fray last year when muscle tissue was obtained from a salt-preserved quagga pelt in a West German museum. The tissue yielded both proteins and genes that could be analyzed (SN:6/9/84, p. 356).
Now the analysis has yielded some results. According to “remarkably concordant” findings on the proteins and on the genes, the quagga was a subspecies of the Plains zebra, says Jerold M. Lowenstein of the University of California at San Francisco. He looked at the binding between a sample of quagga proteins and mixtures of antibodies that bind to blood-serum proteins of each of the extant Equus species. The quagga sample bound more of the antibodies against Plains zebra serum than against the other species. Lowenstein calculates that the quagga relationship with the Plains zebra is six times closer than its relationship with the two other zebra species.
“We had to use special techniques to show the difference,” Lowenstein told SCIENCE NEWS. “There is 99 percent identity on the protein level. All the [Equus] species diverged within the past 5 million years, which is only yesterday in evolutionary terms.”
The quagga-Plains zebra relationship is further supported by the analysis of quagga mitochondrial genes performed by Russell Higuchi and Allan Wilson at the University of California at Berkeley. They find seven times as great a difference between quagga and Mountain zebra DNA as they do between quagga and Plains zebra DNA.
“Stripes, the molecules tell us, do make a zebra,” Lowenstein concludes in the July 18 NEW SCIENTIST, “and the half-striped quagga was a Plains zebra.”

Abstract: In recent years, the noninvasive monitoring of steroid hormone metabolites in feces of mammals and droppings of birds has become an increasingly popular technique. It offers several advantages and has been applied to a variety of species under various settings. However, using this technique to reliably assess an animal's adrenocortical activity is not that simple and straightforward to apply. Because clear differences regarding the metabolism and excretion of glucocorticoid metabolites (GCMs) exist, a careful validation for each species and sex investigated is obligatory. In this review, general analytical issues regarding sample storage, extraction procedures, and immunoassays are briefly discussed, but the main focus lies on experiments and recommendations addressing the validation of fecal GCM measurements in mammals and birds. The crucial importance of scrutinizing the physiological and biological validity of fecal GCM analyses in a given species is stressed. In particular, the relevance of the technique to detect biologically meaningful alterations in adrenocortical activity must be shown. Furthermore, significant effects of the animals' sex, the time of day, season, and different life history stages are discussed, bringing about the necessity to seriously consider possible sex differences as well as diurnal and seasonal variations. Thus, comprehensive information on the animals' biology and stress physiology should be carefully taken into account. Together with an extensive physiological and biological validation, this will ensure that the measurement of fecal GCMs can be used as a powerful tool to assess adrenocortical activity in diverse investigations on laboratory, companion, farm, zoo, and wild animals.

Abstract: A multitude of endocrine mechanisms are involved in coping with challenges. Front-line hormones to overcome stressful situations are glucocorticoids (GCs) and catecholamines (CAs). These hormones are usually determined in plasma samples as parameters of adrenal activity and thus of disturbance. GCs (and CAs) are extensively metabolized and excreted afterwards. Therefore, the concentration of GCs (or their metabolites) can be measured in various body fluids or excreta. Above all, fecal samples offer the advantages of easy collection and a feedback-free sampling procedure. However, large differences exist among species regarding the route and time course of excretion, as well as the types of metabolites formed. Based on information gained from radiometabolism studies (reviewed in this paper), we recently developed and successfully validated different enzyme immunoassays that enable the noninvasive measurement of groups of cortisol or corticosterone metabolites in animal feces. The determination of these metabolites in fecal samples can be used as a powerful tool to monitor GC production in various species of domestic, wildlife, and laboratory animals.

Abstract: The bay-Asturcón pony (A21) population recovery started recently. A total of 297 samples (180 from founder individuals) belonging to the A21 population were genotyped for: a) a set of 15 microsatellites; and b) the presence of the two recessive chestnut alleles reported in the literature (e and ea) on the MC1r gene (locus Extension) and the deletion on the ASIP gene (locus Agouti) associated with recessive black coat in horses. The extent to which the genetic variability of the A21 population could be affected by selection strategies aimed at decreasing the frequency of the chestnut allele was quantified in terms of gene diversity and allelic richness. The possible genetic impact of a controlled introgression of A21 offspring into the black-coated Asturcón (A20) population was also assessed using 261 available A20 genotypes. The wild alleles for the Extension and Agouti loci (E and A, respectively) were the most frequent (77.8% and 59.4%) in the A21 population. Both the e and ea recessive chestnut alleles were identified with frequencies of 21.2% and 1.0%. As expected, the contribution to overall diversity of the founder subpopulation was always higher than that of the A21 offspring subpopulation. Total contribution of the offspring subpopulation to overall allelic richness was negative (- 1.84%), showing that all their alleles were present in the founder subpopulation. Although favourable, the chestnut carrier individuals had poor contributions to overall gene diversity and tended to have negative contributions to allelic richness. The elimination of the chestnut carrier A21 individuals would not affect genetic variability to a significant extent. Therefore, efforts for preserving the genetic variability in the A21 population could focus on a careful planning of matings between individuals free of the recessive chestnut alleles. The expected influence of a controlled introgression of A21 offspring on the genetic variability of the A20 population was always favourable. The gene diversity of the introgressed population was higher than that of the original A20 population for both gene diversity (GDT = -1.2% ± 0.04%) and, particularly, allelic richness (CT = 4.9% ± 0.27%). Very limited gene flow may increase the number of alleles of the A20 population but also would yield a balance of the allelic frequencies at a population level. Therefore, a common breeding policy for the two Asturcón pony populations may ensure the viability of this prominent genetic resource.