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The interplay between biotic and abiotic environments is increasingly recognized as a major determinant of spatial genetic patterns. Among spatial genetic studies, saxicolous or rock-dwelling species remain underrepresented in spite of their strict dependence on landscape structure. Here we investigated patterns and processes operating at different spatial (fine and regional scales) and time scales (using mitochondrial and microsatellite markers) in the rock hyrax (Procavia capensis (Pallas, 1766)). Our focus was on the western seaboard of South Africa and included two recognized biodiversity hotspots (Cape Floristic Region and Succulent Karoo). At fine spatial scale, significant genetic structure was present between four rocky outcrops in an isolated population, likely driven by the social system of this species. At a broader spatial scale, ecological dependence on rocky habitat and population-level processes, in conjunction with landscape structure, appeared to be the main drivers of genetic diversity and structure. Large areas devoid of suitable rocky habitat (e.g., the Knersvlakte, Sandveld, and Cape Flats, South Africa) represent barriers to gene flow in the species, although genetic clusters closely follow climatic, geological, and phytogeographic regions, possibly indicating ecological specialization or adaptation as contributing factors enforcing isolation. Taken together, our study highlights the need to consider both intrinsic and extrinsic factors when investigating spatial genetic structures within species. Key words: Afrotheria, Cape Flats, Knersvlakte, landscape connectivity, landscape genetics, phylogeography, Procavia capensis, rock hyrax. Il est de plus en plus largement reconnu que l'interaction des milieux biotique et abiotique est un déterminant majeur des motifs génétiques spatiaux. Les espèces saxicoles ou vivant dans les rochers demeurent sous-représentées dans les études de génétique spatiale, bien qu'elles soient strictement dépendantes de la structure du paysage. Nous avons étudié les motifs et processus présents à différentes échelles spatiales (fine et régionale) et temporelles (en utilisant des marqueurs mitochondriaux et microsatellites) chez le daman des rochers (Procavia capensis (Pallas, 1766)). Nous nous sommes intéressés plus particulièrement au littoral ouest de l'Afrique du Sud et avons inclus deux points chauds de biodiversité reconnus (la région floristique du Cape et le Karoo succulent). À échelle spatiale fine, une structure génétique significative est présente entre quatre affleurements rocheux dans une population isolée, qui découle probablement du système social de cette espèce. À échelle spatiale plus grossière, une dépendance écologique à des habitats rocheux et des processus à l'échelle de la population, combinés à la structure du paysage, semblent être les principaux moteurs de diversité et de structure génétiques. De grands secteurs exempts d'habitats rocheux convenables (p. ex. le Knersvlakte, le Sandveld et la plaine du Cape, en Afrique du Sud) représentent des barrières au flux génétique au sein de cette espèce, bien que des groupements génétiques concordent de près avec des régions climatiques, géologiques et phytogéographiques, ce qui pourrait indiquer que la spécialisation ou l'adaptation écologique sont des facteurs qui contribuent à l'isolement. Globalement, l'étude souligne la nécessité de tenir compte de facteurs tant intrinsèques qu'extrinsèques dans l'étude des structures génétiques spatiales au sein d'espèces. [Traduit par la Rédaction] Mots-clés : afrothériens, plaine du Cap, Knersvlakte, connectivité du paysage, génétique du paysage, phylogéographie, Procavia capensis, daman des rochers., Introduction Fundamental drivers of biodiversity include the patterns of species distributions in conjunction with their genetic structures (Silvertown and Antonovics 2001). These aspects are both biotically (e.g., dispersal ability, life [...]

Two experiments were conducted to determine the effect of ruminal protein degradability and supplementation frequency on intake, apparent digestibility, N retention, and nutrient flux across visceral tissues of lambs fed a low-quality forage diet. In both experiments, wethers were fed a basal diet of mature crested wheatgrass hay (4.2% CP) for ad libitum consumption plus 1 of 4 supplements: 1) a high RDP supplement provided daily (RDP-D), 2) the high RDP supplement provided on alternate days (RDP-A), 3) a high RUP provided on alternate days (RUP-A), or 4) a 50:50 mixture of the RDP and RUP supplements provided on alternate days. In Exp. 1, 12 lambs (29.9 [+ or -] 2.7 kg initial BW) were used. Forage OM, NDF, and ADF intake were not affected by treatment. Total tract digestibilities (OM, NDF, ADF, and N) were unaffected (P [greater than or equal to] 0.15) by treatment. Neither protein degradability nor supplementation frequency had an effect (P [greater than or equal to] 0.52) on N retention. In Exp. 2, 15 lambs (34 [+ or -] 4 kg initial BW) fitted with indwelling catheters in a hepatic vein, the hepatic portal vein, a mesenteric vein, and a mesenteric artery were used. Release of ammonia N by the portal-drained viscera (PDV) was reduced (P = 0.004) in alternate-day-supplemented lambs compared with RDP-D. Consequently, hepatic uptake of ammonia N was least (P = 0.003) in all alternate-day lambs. Alpha-amino nitrogen (AAN) release by the PDV and hepatic uptake of AAN were not affected by treatment or supplementation frequency. Additionally, hepatic output and PDV uptake of urea N were not affected by treatment. Hepatic N uptake (ammonia N + AAN) accounted for urea synthesized by the liver in all treatments; however, hepatic urea synthesis was approximately 4.5-fold less for RUP-A lambs. This suggests that the provision of AA as RUP may provide a delay in ureagenesis, thus altering the timing of N recycling. Key words: lamb, low-quality forage, nitrogen balance, nitrogen recycling, nutrient flux, protein degradability doi: 10.2527/jas.2009-2246

Elephant-shrews (also called sengis, order Macroscelidea) are small-bodied insectivorous mammals with a strictly African distribution. Fifteen species currently are recognized, of which 9 occur in the southern African subregion. On the basis of molecular, cytogenetic, and morphological evidence, Elephantulus edwardii, the only strictly South African endemic species, is shown to comprise 2 closely related taxa. The new Elephantulus taxon described herein is from the central Nama-Karoo region of Western Cape and Northern Cape Provinces. Important genetic distinctions underpin its delimitation. Sequence data from the mitochondrial cytochrome-b gene and the hypervariable control region as well as 7th intron of the nuclear fibrinogen gene show these 2 taxa to be reciprocally monophyletic. They are separated by 13.8% sequence divergence (uncorrected) based on the 2 mitochondrial segments, and 4.2% based on the nuclear intron sequences. In addition, fixed cytogenetic differences include a centromeric shift, heterochromatic differences on autosomal pairs 1-6, and the number of nucleolar organizer regions. The new species has several subtle morphological and phenotypic characters that distinguish it from its sibling species E. edwardii, the most striking of which is the presence of a tail-tuft, as well as the color of the flanks and the ventral pelage. The abundance, detailed distribution of the new form, and its life-history characteristics are not known, and further studies clearly are needed to determine its conservation status. Key words: Afrotheria, cytogenetics, DNA sequencing, morphology, nomenclature, sengi, taxonomy

Three-year-old Angus x Gelbvieh beef cows nutritionally managed to achieve a BCS of 4 [+ or -] 0.07 (479.3 [+ or -] 36.3 kg of initial BW) or 6 [+ or -] 0.07 (579.6 [+ or -] 53.1 kg of initial BW) at parturition were used in a 2-yr experiment (n = 36/yr) to determine the effects of BCS at parturition and postpartum lipid supplementation on cow adipose tissue lipogenesis. Beginning 3 d postpartum, cows within each BCS were randomly assigned to be fed hay and a low-fat control supplement or supplements with either cracked high-linoleate safflower seeds or cracked high-oleate safflower seeds until d 60 of lactation. Diets were formulated to be isonitrogenous and isocaloric, and safflower seed diets provided 5% DMI as fat. Adipose tissue biopsies were collected near the tail-head region of cows on d 30 and 60 of lactation. Dietary treatment did not affect (P [greater than or equal to] 0.43) adipose tissue lipogenesis. Body condition score at parturition did not affect acetate incorporation into lipid (P = 0.53) or activity of acetyl CoA carboxylase (P = 0.77) or fatty acid synthase (P = 0.18). Lipoprotein lipase activity and palmitate incorporation into triacylglycerol tended to be greater (P = 0.06), and palmitate esterification into total acylglycerols was greater (P = 0.01) in cows with a BCS of 4 at parturition. Mean activity of acetyl-CoA carboxylase (P < 0.001), lipoprotein lipase (P = 0.01), and rate of palmitate incorporation into monoacylglycerol (P = 0.02), diacylglycerol (P = 0.001), triacylglycerol (P = 0.003), and total acylglycerols (P = 0.002) were greater at d 30 than d 60, suggesting a greater proclivity for fatty acid biosynthesis and esterification by adipose tissue at d 30 of lactation. Although dietary lipid supplementation did not affect adipose tissue lipogenesis, results suggest that cows with a BCS of 4 at parturition have a greater propensity to deliver exogenously derived fatty acids to the adipocyte surface and incorporate preformed fatty acids into acylglycerols as stored adipocyte lipid. Additionally, cows in early lactation seemed to be able to synthesize and incorporate more fatty acids into stored lipid than cows during peak lactation. Key words: beef cattle, body condition score, lactation, lipid supplementation, lipogenesis

Three-year-old Angus x Gelbvieh beef cows nutritionally managed to achieve a BCS of 4 [+ or -] 0.07 (479.3 [+ or -] 36.3 kg of BW) or 6 [+ or -] 0.07 (579.6 [+ or -] 53.1 kg of BW) at parturition were used in a 2-yr experiment (n = 36/yr) to determine the effects of prepartum energy balance and postpartum lipid supplementation on cow and calf performance. Beginning 3 d postpartum, cows within each BCS were assigned randomly to be fed hay and a low-fat control supplement or supplements with either high-linoleate cracked safflower seeds or high-oleate cracked safflower seeds until d 60 of lactation. Diets were formulated to be isonitrogenous and isocaloric, and safflower seed supplements were provided to achieve 5% of DMI as fat. Ultrasonic 12th rib fat and LM area were lower (P < 0.001) for cows in BCS 4 compared with BCS 6 cows throughout the study. Cows in BCS 4 at parturition maintained (P = 0.02) condition over the course of the study, whereas cows in BCS 6 lost condition. No differences (P = 0.44 to 0.71) were detected for milk yield, milk energy, milk fat percentage, or milk lactose percentage because of BCS; however, milk protein percentage was less (P = 0.03) for BCS 4 cows. First-service conception rates did not differ (P = 0.22) because of BCS at parturition, but overall pregnancy rate was greater (P = 0.02) in BCS 6 cows. No differences (P = 0.48 to 0.83) were detected in calf birth weight or ADG because of BCS at parturition. Dietary lipid supplementation did not influence (P = 0.23 to 0.96) cow BW change, BCS change, 12th rib fat, LM area, milk yield, milk energy, milk fat percentage, milk lactose percentage, first service conception, overall pregnancy rates, or calf performance. Although cows in BCS of 4 at parturition seemed capable of maintaining BCS during lactation, the overall decrease in pregnancy rate indicates cows should be managed to achieve a BCS >4 before parturition to improve reproductive success. Key Words: Beef Cattle, Body Condition Score, Lipid Supplementation, Prepartum Energy Balance

The Afrotheria, a supraordinal grouping of mammals whose radiation is rooted in Africa, is strongly supported by DNA sequence data but not by their disparate anatomical features. We have used flow-sorted human, aardvark, and African elephant chromosome painting probes and applied reciprocal painting schemes to representatives of two of the Afrotherian orders, the Tubulidentata (aardvark) and Proboscidea (elephants), in an attempt to shed additional light on the evolutionary affinities of this enigmatic group of mammals. Although we have not yet found any unique cytogenetic signatures that support the monophyly of the Afrotheria, embedded within the aardvark genome we find the strongest evidence yet of a mammalian ancestral karyotype comprising 2n = 44. This karyotype includes nine chromosomes that show complete conserved synteny to those of man, six that show conservation as single chromosome arms or blocks in the human karyotype but that occur on two different chromosomes in the ancestor, and seven neighbor-joining combinations (i.e., the synteny is maintained in the majority of species of the orders studied so far, but which corresponds to two chromosomes in humans). The comparative chromosome maps presented between human and these Afrotherian species provide further insight into mammalian genome organization and comparative genomic data for the Afrotheria, one of the four major evolutionary clades postulated for the Eutheria.

The characterization of mouse x rat somatic cell hybrids possessing the B5 to E bands of the mouse chromosome 11 (MMU11) reveals the presence of two hybrids, T16Ad14B and T16Ad19A. Polymerase chain reaction amplification and Southern blot analysis indicates that the hybrids lack the MMU11 loci proximal to and possessing the markers Acrb and Atplb2. The loci distal to and containing the marker Scya2 do exist in the hybrids. Fluorescent in situ hybridization and G-banding of the hybrid T16Ad14B reveals the presence of the 3(super 11) translocation chromosome.

Determination of the genetic divergence within the blue and black South African wildbeests from the allozyme frequencies at 31 loci that code for proteins reveals the polymorphic presence of seven loci in the blue wildbeest and two variable loci in the black wildbeest. The black wildbeest exhibits 0.018 I 0.013 genetic variability while the blue wildbeest exhibits 0.091 plus or minus 0.030 variability. The interspecies genetic distance of 0.059 plus or minus 0.027, obtained from this study, matches the value obtained from mtDNA sequencing.