Temperature Acclimation in Tilapia Sparrmanii: Some Effects of Thiourea

Mastomys natalensis, Aethomys chrysophilus and Saccostomus campestris are three common and widespread rodent species in the Kruger National Park. Chromosomal and protein electrophoretic investigations reveal that these species are in fact complexes of morphologically similar, though genetically distinct, species. Their respective distributions in the Kruger National Park are reported and species diagnostic characters (diploid chromosome number, genitalia, spermatozoa and electromorphs) are presented for the practical identification of the cryptic species. The value of a genetical approach to resolving cryptic species is emphasized with respect to ecological studies.     

The Immunological Response of South African Bulinus Natalensis Antigens to Diploid and Polyploid Bulinus Antisera

Foot muscle antigens of the diploid Bulinus natalensis from Lake Sibayi showed complete immunological correspondence with antiserum prepared from foot muscle tissues of the diploid B. tropicus. On the other hand, strong “non-identity” reactions occurred when B. natalensis antigens were tested with the antiserum prepared from foot muscle of the tetraploid B. coulboisi. It is therefore concluded that B. natalensis is indeed a member of the “tropicusspecies group”, as its chromosome number would imply, and not a diploid member of the more northern polyploid “truncatus species group”, as several morphological characters might suggest.     

Inshore small-mesh trawling survey of the Cape south coast. Part 4. Contributions to the biology of some teleostei and Chondrichthyes

The distributions of eight teleosts and four Chondrichthyes trawled off the Cape south coast are given. The teleosts include Pagellus natalensis, Pomadasys olivaceum, Llthognathus mormyrus, Trachums spp., Galeichthys sp., Atractoscion aequidens, Cheimerius nufar and Sphyraena africana. The Chondrichthyes are Squalidae, Myliobatis aquila, Rhinobatos annulatus, Dasyatis pastinacus and Callorhinchus capensis. Incidental observations on the biology of these species are also given. Extensive inshore marine nursery areas for the teleost species were identified. The importance of this with respect to inshore trawling is noted.     

青藏高原东缘３种风毛菊属植物的核型研究

 本研究报道了产于青藏高原东缘３种风毛菊属植物的染色体数目和核型。研究结果表明,３个种的染色体数目和核型如下：甘肃风毛菊为２ｎ＝２ｘ＝３２＝１２ｍ＋１６ｓｍ＋４ｓｔ,核型属２Ｂ型;大耳叶风毛菊为２ｎ＝２ｘ＝２６＝１０ｍ＋１４ｓｍ＋２ｓｔ,核型属２Ａ 型;波缘风毛菊为２ｎ＝２ｘ＝２６＝６ｍ＋２０ｓｍ,核型属２Ｂ型;这３个种均为二倍体,并且在染色体中均未发现随体和Ｂ染色体。     

Physa mosambiquensis (Clessin, 1886) rediscovered?

An exotic fresh-water gastropod recently discovered in South Africa is identified as Aplexa (Stenophysa) marmorata (Physidae) and is considered conspecific with a population known from West Africa since at least 1911 and a single record from Mozambique dating from 1886. It is speculated that these introductions could have occurred via the Portuguese slave trade during the 16th and 17th centuries. A key to A. marmorata, another introduced physid Physa acuta and the indigenous, sinistral genus Bulinus is presented.     

A new and unusual species of Parachiton (Mollusca: Polyplacophora) from South Africa

A new species of the genus Parachiton, P. hodgsoni n.sp., which inhabits shallow water off the South African coast, is described. The radula is unusual for the genus Parachiton. It consists of about 160 transverse rows of very small mature teeth of which the major lateral teeth have very narrow tridentate cusps. The intermediate valves are granulose with the granules arranged in widely spaced, longitudinal rows on the central area of the valves. There are 20–31 longitudinal rows on the central areas of the intermediate valves. Variability in the morphology of the tail valve is shown.     

Avoidance responses of some indigenous and exotic freshwater pulmonate snails to leech predation in South Africa

The avoidance behaviour elicited from four species of freshwater pulmonate snails, Physa acuta and Aplexa marmorata (Physidae), Bulinus tropicus (Planorbidae) and Lymnaea natalensis (Lymnaeidae), following contact with a molluscivorous leech Hebbdella conifera (Glossiphoniidae), was examined experimentally. Although H. conifera showed no species preference for any of those species it attacked, the physids, both exotics, were killed less often than would be expected by chance. The indigenous species, B. tropicus and L natalensis, were more susceptible to leech attack than the introduced species. Size-preference trials using P. acuta showed decreased susceptibility to leech attack with an increase in snail size. These results are interpreted with reference to the mode of leech attack and to differences in snail morphology.     

R132 mutations in canine isocitrate dehydrogenase 1 (IDH1) lead to functional changes

Glioma is the second most common intracranial neoplasia in dogs, but the pathogenic mechanisms remain unclear. In humans, isocitrate dehydrogenase 1 (IDH1) is frequently mutated in gliomas. Although almost all human IDH1 mutations have been identified as involving the Arg132 codon, few studies have reported structural, functional, and mutational information for canine IDH1. Therefore, in this study, we cloned the canine IDH1 homologue and used PCR mutagenesis to substitute the wildtype (WT) Arg132 with His (R132H) or Ser (R132S). WT and mutated IDH1 were overexpressed in HeLa cells, and their presence was confirmed by immunoblotting and immunocytochemistry using mutation-specific antibodies. The IDH1 activity between WT, R132H, and R132S transfectants was compared by measuring the production of NADH and NADPH. NADPH production in R132H and R132S transfectants was lower than that in WT, but NADH levels were not significantly different. Finally, we detected increased expression of hypoxia inducible factor 1 alpha (HIF-1α) in the R132H and R132S transfectants. These results indicated that the canine IDH1 Arg132 mutation has the potential to induce carcinogenesis in canine somatic cells.     

Chromosomal rearrangements occurred repeatedly and independently during species diversification in Malagasy geckos,genus Paroedura

We conducted a phylogenetic study through karyological data, by standard staining and Ag-NOR banding, and molecular analysis (by 12S and 16S mitochondrial rRNA genes and nuclear gene C-mos) on 11 species of Malagasy geckos, genus Paroedura, and two relatives (Ebenavia inunguis and Uroplatus phantasticus). Ebenavia inunguis and U. phantasticus had 2n = 36 telocentric elements, NORs on the first chromosome pair in E. inunguis, and on the third chromosome pair in U. phantasticus. All examined Paroedura showed NORs on the smallest chromosome pair; moreover, six of the eleven examined species show a 2n = 36 karyotype, with a pair of metacentrics and 17 telocentric pair. The remaining species exhibited karyotypes with a diploid chromosome number ranging from 2n = 31 to 2n = 38. We assume that these karyotype assemblages derived from the 2n=36 karyotype by cryptic and/or simple rearrangements, such as inversions, fissions and fusions. Furthermore, molecular and/or chromosomal data indicate that Paroedura is a monophyletic genus, in which chromosome rearrangements occurred repeatedly and independently during the specific diversification. Moreover both P. bastardi and P. gracilis in current definitions are paraphyletic assemblages of several related species, since their population proves more closely related to P. ibityensis or P. oviceps than co-specific populations.     

Natural infection by Cryptosporidium sp., Giardia sp. and Eimeria leuckarti in three groups of equines with different handlings in Rio de Janeiro, Brazil

To detect Cryptosporidium sp., Giardia sp. and Eimeria leuckarti in horses, fecal samples were collected from three different handling horse groups from the state of Rio de Janeiro, Brazil. Group A was composed of “Mangalarga Marchador” pure breed horses, Group B was formed by horses of a Military Corporation and Group C by stray horses captured by the Center of Zoonosis Control Paulo Dacorso Filho. A total of 396 fecal samples were collected, 212 samples from Group A, 154 samples from Group B and 30 from Group C. The material was submitted to the centrifugation - flotation technique and staining by the safranin-methylene blue technique and analyzed. Oocysts of Cryptosporidium sp. were identified in 0.75% of the samples (n = 3); cysts of Giardia sp. in 0.5% (n = 2) and oocysts of E. leuckarti in 0.5% (n = 2). One case of E. leuckarti in group A and one of Cryptosporidium sp. in group B were observed. In group C were observed two cases of Cryptosporidium, two of Giardia and one of E. leuckarti,. Horses of group C were more parasitized by the three protozoans than animals from the other groups (p < 0.01). It was possible to verify that factors related to the animals, like host individual susceptibility and sanitary factors may influence the occurrence of natural infections by gastrointestinal protozoans, although the age did not have influence. This study reports, for the first time, the occurrence of Cryptosporidium sp., Giardia sp. and E. leuckarti in equines of the State of Rio de Janeiro.     

The Birds of the Alien Acacia Thickets of the South Western Cape

The plough shell, Bullia rhodostoma (Mollusca: Gastropoda), has been studied on an open sandy beach where it is a common scavenger. Samples taken over a year indicate hatching of young individuals from December to February. They reach a length of about 10 mm after 1 year and 40 mm after 10 years. The von Bertalanffy growth equation is L_t = 47 (1 - e^{-0,19(t+0,23)}) and the annual mortality rate is 0,79. Mean decalcified dry biomass is 209 mg m^-2 and production by growth 189 mg m^-2 y^-1 giving a P/B of 0,9. Most production by adults (>15 mm shell length) goes into reproduction, particularly In the females which grow larger than the males. Production by reproduction is estimated to be about 135 mg m^-2 y^-1. Average calorific values are 19,04 kJ g^-1 dry tissue     

The karyotype and taxonomie status of Cryptomys hottentotus dartingi (Rodentia: Bathyergidae)

Cytogenetic analyses were performed on twenty specimens referable to Cryptomys hottentotus darling! from north eastern Zimbabwe. In comparison to the southern subspecies C. h. hottentotus (aFN = 102) and C. h. natalensis (aFN = 100), C. h. darHngi showed the same diploid number (2n = 54), but a striking reduction in the fundamental number (aFN = 80). C-banding analysis suggests that chromosome differentiation arose most probably by pericentric inversions. The magnitude of the karyotypic differences is assumed to represent reproductive isolation and consequently the specific status for the dartingi cytotype is recommended.     

Karyotypes of three shrew species (Soriculus nigrescens,Episoriculus caudatus and Episoriculus sacratus) from Nepal

The karyotypes of three shrew species (Mammalia, Soricomorpha, Soricidae) from Nepal were examined for the first time. Based on the karyotypes and overall differences in skull size, the current Episoriculus caudatus appeared to include two distinct species: the larger E. caudatus and the smaller Episoriculus sacratus. Episoriculus sacratus has three subspecies, E. s. soluensis in Nepal and Sikkim, E. s. umbrinus in Assam, Myanmar and the Yunnan Province of China, and E. s. sacratus in the Sichuan Province of China. Soriculus nigrescens had a diploid chromosome number (2n) and fundamental number (FN), including two X chromosomes, of 64 and 92, respectively, consisting of 11 metacentric or submetacentric, two subtelocentric and 18 acrocentric pairs of autosomes, a metacentric X and an acrocentric Y chromosome. Episoriculus sacratus soluensis had 2n = 74 and FN = 126, consisting of 12 metacentric or submetacentric, 13 subtelocentric and 11 acrocentric pairs of autosomes, a submetacentric X and an acrocentric Y chromosome. Episoriculus caudatus had 2n = 60 and FN = 118, consisting of 19 metacentric or submetacentric, nine subtelocentric and one acrocentric pair of autosomes, a subtelocentric X and an acrocentric Y chromosome. The karyotypes of these three species are characterized by their large 2n and FN values compared with other Soricidae.     

Exploring the metabolome of seminal plasma in two different horse types: Light versus draft stallions

The application of the ‘omics’ studies in the field of animal reproduction has been aimed at identifying novel biomarkers of fertility since the last few years. When assessing reproductive efficiency in horses, breed should also be taken into account as it can influence semen quality and fertility. Considering the growing interest in metabolomic analysis to evaluate male fertility, we aimed to investigate the metabolomic profile of seminal plasma in two different horse breeds. Twelve healthy stallions, n.6 American Quarter Horse (AQH) and n.6 Italian Draft Horse (IDH) stallions, regularly used for artificial insemination, were included in the study. Two semen collections, performed 30-day apart, were considered for the assessment of semen parameters including gel-free volume, spermatozoa (spz) concentration, spz progressive motility and seminal plasma analysis by ¹H-NMR.Semen characteristics differed between IDH and AQH (p < .05) as well as the first cycle conception rate that was higher in AQH than IDH (p = .001). Metabolomic analysis quantified 56 molecules in equine seminal plasma, with 11 metabolites showing different concentrations in IDH compared to AQH (p < .05).This study provided evidence of differences in seminal plasma metabolites' concentrations between studied horse types, highlighting specific metabolomic fingerprints characterizing AQH and IDH sperm.     

Participation of phosphofructokinase,malate dehydrogenase and isocitrate dehydrogenase in capacitation and acrosome reaction of boar spermatozoa

The aim of this work was to determine the enzymatic activity of phosphofructokinase (PFK), malate dehydrogenase (MDH) and isocitrate dehydrogenase (IDH) in boar spermatozoa and study their participation in bicarbonate‐induced capacitation and follicular fluid‐induced acrosome reaction. Enzymatic activity of these enzymes was determined spectrophotometrically in extracts of boar spermatozoa. Sperm suspensions were incubated in the presence of bicarbonate (40 mM), a well‐known capacitation inducer, or follicular fluid (30%), as an acrosome reaction inducer, and different concentrations of oxoglutarate, oxalomalate and hydroxymalonate, inhibitors of PFK, IDH and MDH, respectively. Capacitation percentages were determined by the fluorescence technique of chlortetracycline (CTC), and true acrosome reaction was determined by trypan blue and differential–interferential contrast, optical microscopy. The activity of PFK in boar spermatozoa enzymatic extracts was 1.70 ± 0.19 U/10¹⁰ spermatozoa, the activity of NAD‐ and NADP‐dependent IDH was 0.111 ± 0.005 U/10¹⁰ and 2.22 ± 0.14 U/10¹⁰ spermatozoa, respectively, and the activity of MDH was 4.24 ± 0.38 U/10¹⁰ spermatozoa. The addition of the specific inhibitors of these enzymes prevented sperm capacitation and decreased sperm motility during capacitation and inhibited the acrosome reaction (AR), without affecting the sperm motility during this process. Our results demonstrate the participation of PFK, IDH and MDH in bicarbonate‐induced capacitation and follicular fluid‐induced acrosome reaction in boar spermatozoa, contributing to elucidate the mechanisms that produce energy necessary for these processes in porcine spermatozoa.     

Cytogenetic mapping of 11 functional genes to chicken chromosomes by fluorescence in situ hybridization

With chicken bacterial artificial chromosome (BAC) DNA as probes, 11 non‐assigned functional genes were localized to chicken chromosomes 1 or 2 by fluorescence in situ hybridization (FISH). The 11 genes and their chromosomal positions are as follows: ALVEB5, 1p26‐24; ACO2, 1p16‐14; HSP108, 1p14‐13; CD4, 1q11; HSD3B; 1q11; SOD1, 1q14‐21; LAMP1, 1q24‐31; P2Y5, 1q35‐36; EN2, 2p31‐24; NPY, 2p14‐13 and CA2, 2q31‐32. Metaphase chromosome spreads used for hybridization were prepared from embryonic chicken fibroblast cultures. The gene position was identified according to the international standardized G‐banded karyotype of chicken by measuring the relative fractional length from the telomere of the p‐arm to the hybridization signal (FLpter). The 11 genes mapped newly will enrich the cytogenetic map and serve as additional anchor markers for integrating the cytogenetic map with the genetic map of chicken.     

Three new Chromadoropsis species (Nematoda,Desmodoridae) from Southern Africa and the North Sea

Three new Chromadoropsis species with four pharyngeal bulbi are described from Southern Africa, Namibia (S.W.A.) and the North Sea. C. granulosus sp.nov. is described from a sandy beach near Port Elizabeth. This species is characterized by a very distinct layer of yellow granules just below the cuticle. C. namibiensis sp.nov. is described from a sandy beach at Langstrand, Namibia. This species can be distinguished by the length and shape of the gubernaculum and spicules as well as the size of the capitulum. C. longispiculosa sp.nov. is described from the North Sea and is characterized by the long spicules and the presence of numerous porids. The genus Chromadoropsis Filipjev, 1918 is revised.     

First account of the metazoan parasite fauna of oilfish Ruvettus pretiosus Cocco, 1829 (Perciformes: Gempylidae) in South African waters

Parasites are an important but neglected component of ecosystems that can be used as indicators of host biology and ecology. In the present study, the metazoan parasite assemblage of Ruvettus pretiosus, an understudied but widely distributed predatory gempylid, caught off South Africa was surveyed. A total of seven parasite taxa, including four new infection records (Bolbosoma capitatum, Rhadinorhynchus sp., Hepatoxylon trichiuri and Anisakis sp.), two new locality records (B. capitatum and Rhipidocotyle sp.) as well as the ectoparasitic copepod Sagum foliaceus and the cestode Tentacularia coryphaenae were recovered from the eight specimens examined.     

柳蚕异柠檬酸脱氢酶基因cDNA的克隆与表达分析

异柠檬酸脱氢酶(isocitrate dehydrogenase,IDH)是生物体内一种重要的氧化还原酶。根据已报道的烟酰胺腺嘌呤二核苷酸磷酸异柠檬酸脱氢酶(NADP-IDH)基因的保守性序列设计引物,以柳蚕(Actias seleneHubner)蛹脂肪体cDNA为模板,经PCR扩增获得了柳蚕IDH基因的部分序列。该序列长1 269 bp,编码412个氨基酸,与家蚕IDH基因的cDNA序列同源性达82.5%。柳蚕IDH与果蝇、赤拟谷盗、斑马鱼、人、大鼠、库蚊、人体虱、恶性疟原虫IDH的氨基酸序列同源性在70%左右,具有较高的保守性。半定量PCR检测结果表明,柳蚕IDH基因在蛹期不同组织中均有表达,且表达量没有显著差异。     

The hen's egg: Shell shape and size parameters and their interrelations

The occurrence of a crack in an egg shell depends in part on the local strength of the shell, which in turn depends on its curvatures as well as its thickness, and therefore on its shape. Selection for shell shape is therefore needed; but before the breeder can do this he must have a rapid and accurate method of quantifying shell shape, and knowledge of the factors that affect its variation.

A procedure is described whereby nine measurements of an egg shell—length, maximum breadth, distance from the plane of maximum breadth to the broad pole and the distances by which each pole projects into annuli of diameters 1.5, 2.5 and 3.5 cm—are used to obtain an equation describing the profile of the egg in polar coordinates. It has five parameters that measure, independently, five shell characteristics: scale, aspect (breadth‐to‐length ratio), skewness, marilynia (concordant bulging between the poles and the plane of maximum breadth) and platycephaly (discordant bulging). Egg volume and superficial area can be obtained by integration, shell curvatures by differentiation. An experiment in which the computed volumes of 61 eggs from 19 hens of four strains were compared with the volumes measured by water displacement failed to detect, in single‐yolked eggs, any discrepancy not attributable to random measurement error, which was 0–2 per cent of mean egg volume.

Aspect, marilynia and platycephaly are shown to be correlated inter se and with egg size; differences between hens and strains in respect of them are shown to exist. Making the shell measurements could be automated and use of the method could lead to improved efficiency of selection for egg size as well as shape.