Sequence comparison of mitochondrial tRNA genes and origin of light strand replication in Bos taurus and Nellore (Bos indicus) breeds

Although the complete bovine mitochondrial DNA molecule has been previously sequencedand sequence comparisons of the mitochondrial displacement loop have been performed, detailed sequence information is limited on coding regions of mitochondrial DNA within and among breeds of Bos taurus and Bos indicus. This study analysed polymorphism of the mitochondrial DNA transfer RNA genes for trypto-phan, alanine, asparagine, cysteine, tyrosine and the origin of light strand replication among Ayrshire, Canadian, Belgium Blue, Brown Swiss, Hereford, Jersey, Limousine, Piedmon-taise, Red Angus, Simmental (Bos taurus) and a Nellore (Bos indicus). Nucleotide sequence analysis of a 420-bp fragment of mitochondrial DNA comprising the five transfer RNA genes showed 100% homology among single individuals of the Bos taurus breeds. The Nellore breed showed guanine to adenine substitutions in the DHU arm of asparagine tRNA and in the origin of light-strand replication. This equates to a 0.5% sequence difference between the Nellore andBos taurus breeds and may reflect an independent evolutionary origin of the species.     

Stem borer infestation of cereal crops in Jere,the Sudan-Sahelian savanna region of Nigeria

Field data collected during the rainy season of two years, 2010 and 2011, were used to determine the per cent plant infestation and stem borer abundance on cultivated cereal crops grown by farmers' in Jere or the Sudan-Sahelian savanna ecological region of Nigeria. Stem borers were recovered using destructive sampling. Mean total per cent plant infestation and stem borer abundance per farmers' field were significantly higher on millet (40% and 25 individuals, respectively) and sorghum (30% and 21 individuals, respectively) than on maize (19% and 13 individuals, respectively). Of the five stem borer species found in this study, Coniesta ignefusalis (Lepidoptera: Pyralidae) (3.5)/Chilo sp. nr. aleniellus (Lepidoptera: Crambidae) (2), Busseola fusca (Lepidoptera: Noctuidae) (3.1)/Sesamia calamistis (Lepidoptera: Noctuidae) (2.4) and S. calamistis (2.9), with significantly higher number of individuals per plant, tended to be more important pests on millet, sorghum and maize crops, respectively. Although, mean total per cent plant infestation and abundance of stem borers in this study were generally moderate, further studies on the effects of different types of cereals intercropping (locally practiced) on stem borer infestation and abundance should ascertain the true importance of these pest species in the Sudan-Sahelian savanna ecological region of Nigeria.     

A novel polymorphism of GDF5 gene and its association with body measurement traits in <Emphasis Type="Italic">Bos taurus</Emphasis> and <Emphasis Type="Italic">Bos indicus</Emphasis> breeds

Body measurement traits, influenced by genes and environmental factors, play numerous important roles in the value assessment of productivity and economy. Growth differentiate factor 5 (GDF5), involved in the development and maintenance of bone and cartilage, is an important candidate gene for body measurement traits selection through marker-assisted selection (MAS). In this study, based on the PCR-RFLP technology, we discovered and evaluated the potential association of the single nucleotide polymorphism (SNP) (T586C in exon 1) of the bovine GDF5 gene with body measurement traits in 985 Bos taurus breed, 42 Bos indicus breed and 76 Bos indicus × Bos taurus individuals. As the SNP marker, there were the significant effects on the Body length (BL) in the Bos taurus (BT) and Bos indicus × Bos taurus (BMY) populations (P < 0.05). In BT population, animals with the genotype TT had lower mean values for BL and Hip width (HW) than these with the TC and CC genotype (P < 0.01). In BMY population, animals with the genotype TC had lower mean values for BL than these with the genotype CC (P < 0.05). These results suggest that the SNP of the GDF5 gene could be a very useful genetic marker for body measurement traits in the bovine reproduction and breeding.     

Comprehensive analysis of the mitochondrial DNA diversity in Chinese cattle

Complete mitochondrial DNA D‐loop sequences of 1105 individuals were used to assess the diversity of maternal lineages of cattle populations in China. In total, 250 taurine and 88 zebu haplotypes were identified. Five main haplogroups—T1a, T2, T3, T4 and T5—were identified in Bos taurus, whereas Bos indicus harbored two haplogroups—I1 and I2. Our results suggest that the distribution of T1a in Asia was concentrated mainly in the northeast region (northeast China, Korea and Japan); haplogroups T2, T3 and T4 were predominant in Chinese cattle; and T5 was sporadically detected in Mongolian and Pingwu cattle. In contrast to the widespread presence of I1, I2 was distributed only in southwestern China (Yunnan‐Guizhou Plateau and the Tibet Autonomous Region) and Xinjiang Uygur Autonomous Region. This is the first time that all five taurine haplogroups and two zebu haplogroups have been found in Mongolian cattle. In addition, eight individuals in Tibetan cattle carried the Bos grunniens mtDNA type. The high mtDNA diversity (H = 0.904 ± 0.008) and the weak genetic structure among the 57 Chinese cattle breeds/populations are consistent with their complex historical background, migration route and ecological environment.     

Population structure and ancestry of Qinchuan cattle

The aim of this study was to estimate population structure and ancestry of Qinchuan cattle by genotyping 27 individuals using the GeneSeek HD 77k BeadChip, and another 1355 cattle representing breeds distributed worldwide, which had been genotyped using the Illumina Bovine 50k BeadChip. Qinchuan cattle were characterized by a dominant Bos taurus ancestry, accompanied by a considerable proportion of Bos indicus ancestry based on principal components analysis and supervised admixture analysis. A small proportion of Bos javanicus ancestry was detected as well. A similar admixture pattern in both Qinchuan and Turkish cattle breeds reflects their similar degrees of zebu introgression. Our study presents a relatively clear view of the population structure and ancestry of Qinchuan cattle, serving to benefit our understanding of this breed and leading to better targeted conservation approaches moving forward.     

Management of Fruit Flies (Diptera: Tephritidae) of the Most Perishable Fruits

We investigated to minimize the dependency on the use of chemicals and thus develop safe and environmental friendly control program for the most perishable fruits i.e., apple,‘ber’, guava and mango. Our findings on the composition of fruit fly species reveal that Bactrocera dorsalis was dominant on apple (33.96% existence), Corpomya incompleta on‘ber’(51.91% existence) and Bactrocera zonata on guava (49.62% existence) and mango (74.66% existence). The correlation between population and infestation percentage was non‐significant in apple orchards, whereas positive and highly significant in between population and infestation, as well as on the cumulative basis in‘ber’, guava and mango orchards during 1998‐1999. Hoeing, baiting and methyl eugenol were statistically equal resulting about 77% decrease in infestation. The maximum control of 91.68% was observed where all four‐control operations including Dipterex® were integrated together. Weather factors, when computed together, had maximum effect on population fluctuation and infestation with rainfall contributing the major role. For guava fruits, the months of August (14.06A individuals/trap/day) and September (13.81A individuals/trap/day) were important, resulting in maximum infestation percentage of 10.76 to 14.74%, respectively.     

Stem borer's species composition,abundance and infestation on maize and millet in Maiduguri,Nigeria

The species composition, abundance and plant infestation of stem borers attacking maize and millet were investigated in farmers' fields during the cropping season of 2010 and 2011 in Maiduguri, Nigeria. Stem borers were collected via destructive sampling. In total, three stem borer species (Busseola fusca, Sesamia calamistis and Coniesta ignefusalis) were found, of which S. calamistis (64%) and C. ignefusalis (72%), respectively, were predominant on maize and millet. Across both years, whereas mean plant infestation ranged from 4.8% on millet to 20.8% on maize, mean stem borer abundance ranged from 1.6 individuals on millet to 13.8 individuals on maize. Mean total plant infestation and stem borer abundance varied with different years and both were significantly higher during the 2010 than 2011 cropping season. In spite of the generally low stem borer abundance per farmers' field, plant infestation particularly on maize plants seems to be moderate during different years.     

mtDNA Diversity and genetic lineages of eighteen cattle breeds from <Emphasis Type="Italic">Bos taurus </Emphasis>and<Emphasis Type="Italic"> Bos indicus</Emphasis> in China

In order to clarify the origin and genetic diversity of indigenous cattle breeds in China, we carried out phylogenetic analysis of representatives of those breeds by employing mitochondrial gene polymorphism. Complete cyt b gene sequences, 1140 bp in length, were determined for a total of 136 individuals from 18 different breeds and these sequences were clustered into two distinct genetic lineages: taurine (Bos taurus) and zebu (Bos indicus). In analysis of the cyt b gene diversity, Chinese cattle showed higher nucleotide (0.00923) and haplotype diversity (0.848) than the reports from other studies, and the animals from the taurine lineage indicated higher nucleotide diversity (0.00330) and haplotype diversity (0.746) than the ones from the zebu lineage (0.00136; 0.661). The zebu mtDNA dominated in the southern breeds (63.3–100%), while the taurine dominated in the northern breeds (81.8–100%). Six cattle breeds from the central area of China exhibited intermediate frequencies of zebu mtDNA (25–71.4%). This polymorphism revealed a declining south-to-north gradient of female zebu introgression and a geographical hybrid zone of Bos taurus and Bos indicus in China.     

Tick-susceptible Bos taurus cattle display an increased cellular response at the site of larval Rhipicephalus (Boophilus) microplus attachment, compared with tick-resistant Bos indicus cattle

Cattle demonstrate divergent and heritable phenotypes of resistance and susceptibility to infestation with the cattle tick Rhipicephalus (Boophilus) microplus. Bos indicus cattle are generally more resistant to tick infestation than Bos taurus breeds although large variations in resistance can occur within subspecies and within breed. Increased tick resistance has been previously associated with an intense hypersensitivity response in B. taurus breeds; however, the mechanism by which highly resistant B. indicus cattle acquire and sustain high levels of tick resistance remains to be elucidated. Using the commercially available Affymetrix microarray gene expression platform, together with histological examination of the larval attachment site, this study aimed to describe those processes responsible for high levels of tick resistance in Brahman (B. indicus) cattle that differ from those in low-resistance Holstein-Friesian (B. taurus) cattle. We found that genes involved in inflammatory processes and immune responsiveness to infestation by ticks, although up-regulated in tick-infested Holstein-Friesian cattle, were not up-regulated in Brahman cattle. In contrast, genes encoding constituents of the extracellular matrix were up-regulated in Brahmans. Furthermore, the susceptible Holstein-Friesian animals displayed a much greater cellular inflammatory response at the site of larval R. microplus attachment compared with the tick-resistant Brahman cattle.     

Monogenean infestations and mortality in wild and cultured Red Sea fishes

Hyperinfection by the gill-infesting monogeneanAllobivagina sp. (Microcotylea) caused mass mortalities in juveniles ofSiganus luridus cultured in seawater earthen ponds and holding tanks in Eilat (Gulf of Aqaba, Red Sea). Other species ofSiganus and adults ofS. luridus cultured in the same systems acquired a low intensity of infestation. Most hyperinfected fish were emaciated and anaemic with hematocrit values below 10 %. Skin and mouth infestations by the monogeneanBenedenia monticelli (Capsaloidea) caused mass mortalities in grey mullets (Mugilidae). These mortalities occurred in large individuals in wild populations ofLiza carinata from lagoonal habitats in the Gulf of Suez and in most species of grey mullets cultured in Eilat. The intensity of infestation correlated positively with severity of infestation, and the common sites of infestation corresponded with areas of severe pathological alterations. Spontaneous recovery followed the climax of an epizootic, both for infestedS. luridus and infested grey mullets. Decline in infestation coincided with remission of the pathological signs.     

Competition,facilitation or mediation via host? Patterns of infestation of small European mammals by two taxa of haematophagous arthropods

1. We studied the effect of flea infestation on the pattern of tick (Ixodes ricinus and Ixodes trianguliceps) infestation on small mammals. 2. We asked (1) whether the probability of an individual host being infested by ticks was affected by its infestation of fleas (number of individuals and species) and (2) whether the abundance and prevalence of ticks in a host population was affected by the abundance, prevalence, level of aggregation, and species richness of fleas. 3. The probability of a host individual being infested by ticks was affected negatively by flea infestation. At the level of host populations, flea abundance and prevalence had a predominantly positive effect on tick infestation, whereas flea species richness had a negative effect on tick infestation. 4. The effect of flea infestation on tick infestation was generally greater in I. ricinus than in I. trianguliceps, but varied among host species. 5. It can be concluded that the effect of fleas on tick infestation of small mammals may be either negative or positive depending on the level of consideration and parameters involved. The results did not provide support for direct interactions between the two ectoparasite taxa, but suggested population and community dynamics and the defence system of the hosts as possible factors.     

Phylogenetic analysis of the tribe Bovini using microsatellites

The objective of the present study was to determine if the generally accepted phylogenetic relationships in the tribe Bovini correspond to a phylogenetic scheme derived from polymorphisms at 20 bovine microsatellite loci. This study comprises 17 representative populations: eight Bos taurus, two Bos indicus, one Poëphagus, one Bibos, one Bison, three Bubalus and one Syncerus. Phylogenetic analyses using (δμ)² and chord (D_C) distances revealed substantial divergence among species. Neighbor‐joining trees with both distance measures showed only minor differences. Bos taurus and Bos indicus grouped first, followed by Bos frontalis (Mithan) and Bos grunniens (Yak), Bison bison branched off next and Bubalus bubalis and Syncerus caffer emerged as the two most divergent species from the Bos clade. These findings would suggest that Bos, Poëphagus, and Bibos should be integrated into the Bos genus with each group classified as a subgenus. On the other hand, Bison, Bubalus and Syncerus should each be considered a separate genus. Direct estimates of the divergence times were calculated using the (δμ)² genetic distance. Bos taurus and Bos indicus were estimated to have diverged 0·31–0·82 MYA, Bos and Poëphagus: 0·57–1·53 MYA, Bos and Bibos: 0·57–1·52 MYA, Bos and Bison: 0·46–1·23 MYA, Bos and Bubalus: 1·85–4·93 MYA and Bos and Syncerus: 0·98–2·61 MYA.     

Infestation of the invasive mollusc <Emphasis Type="Italic">Crepidula fornicata</Emphasis> by the native shell borer <Emphasis Type="Italic">Cliona celata</Emphasis>: a case of high parasite load without detrimental effects

The temporal prevalence of the widespread boring sponge Cliona celata and its effects were analysed in a population of the invasive mollusc Crepidula fornicata. This mollusc produces extra shell material when infested with the endolithic sponge, suggesting that infestation may be detrimental for C. fornicata growth and/or reproduction. For 37 months, size, sex, female reproductive status and sponge-infestation stage were recorded for 300 individuals sampled every month in the Bay of Morlaix (France). In the 12,049 individuals examined, the prevalence of C. celata was high with a monthly average of 43.1% of the individuals hosting the sponge. The relative proportion of heavily infested individuals generally increased over time. Nevertheless, a cyclic decrease occurred every 10 months, suggesting putative episodes of mortality of heavily infested individuals. The gregarious behaviour of the mollusc seemed to promote the high prevalence of the sponge, which may propagate through contact between neighbouring C. fornicata individuals. Due to the sex-size relationship in protandrous C. fornicata, females were far more infested than males. We did not find evidence for a cost of producing extra shell material on somatic growth or on female fertility, and the boring sponge is unlikely to substantially affect the sex-change patterns in C. fornicata. The limited effects of the endolithic sponge on C. fornicata contrasts with the documented damage to some local species, including commercially exploited shellfish, suggesting that C. fornicata may alter the infestation dynamics in the surrounding native community. Dedicated studies are now needed to investigate the extent and mechanisms of these species interactions.     

The relative influence of temperature and humidity on cutaneous function in Bos indicus and Bos taurus females

The relative importance of dry- and wet-bulb temperatures on cutaneous function inBos indicus andBos taurus females under humid tropical climatic conditions was evaluated. The parameters investigated were sweating rate and skin temperature, while the species utilised were zebu White Fulani (Bos indicus) and German Brown and German Black and White (Bos taurus).The sweating rate, irrespective of breed, differed with the site of sampling and was more influenced by dry-bulb (59%) than by wet-bulb temperature (41%). Skin temperature responded more to wet-bulb temperature in White Fulani and German Black and White cattle, but not in German Brown cattle.It is concluded that the response of the animals, with respect to sweating, was similar but that the efficiency of sweating, judged by the lowering of skin temperature, was higher inBos indicus than inBos taurus. This, in part, may explain the higher degree of comfort demonstrated byBos indicus under tropical conditions.     

Methemoglobin reductase in three species of Bovidae

Isoelectric focusing of red cell hemolysates revealed several isozymes that stain for NADH-methemoglobin reductase. Evidence for two different genetic loci controlling the banding patterns was obtained. One locus controlled a single band present in all animals tested. The second locus controlled ten different banding patterns that could be accounted for by four codominant alleles. Band B occurred in Bison bison. Bands A and C occurred in Bos indicus and band D occurred in both Bos indicus and Bos taurus. Bands A, C, and D were not observed in Bison bison and bands A, B, and C were not observed in Bos taurus.     

EFFECT OF ECTOPARASITIC MITES ON SEXUAL SELECTION IN A SONORAN DESERT FRUIT FLY

We conducted a field study and a laboratory experiment to test whether ectoparasitic mites, Macrocheles subbadius, generate parasite-mediated sexual selection in the Sonoran desert endemic fruit fly, Drosophila nigrospiracula. Male flies gather on the outer surfaces of necrotic saguaro cacti where they engage in male–male competitive interactions and vigorous female-directed courtship. At these sites, operational sex ratios were significantly skewed toward males. The degree to which mites were aggregated among flies varied across the 25 fly populations sampled. The degree of mite aggregation across fly populations was strongly positively related to the mean number of mites per fly (intensity of infestation). Both the intensity and prevalence of infestation (fraction of flies infested) increased with the age of the cactus necrosis. Infested flies of both sexes were significantly less likely to be found in copula than uninfested flies, and mean intensity of infestation was significantly more pronounced in noncopulating than in copulating flies. The effect of attached mites on copulatory success exhibited dose-dependency, and this effect was more stringent in males: males or females with more than two and four mites, respectively, were never found in copula. The magnitude of parasite-mediated sexual selection was estimated for 12 fly populations by calculating selection differentials for each sex separately. The relation between intensity of infestation and magnitude of parasite-mediated sexual selection was stronger in males but significant for both sexes. We also assayed copulatory success of field-caught males in the laboratory, both during infestation and after experimental removal of mites. Males infested with two mites copulated less frequently than uninfested individuals, and in mating trials after mites had been removed, previously infested males copulated as many times as flies with no history of infestation. These findings, and the lack of difference in the number of mite-induced scars on copulating and single individuals in nature, strongly suggest that the reduced copulatory success of infested flies is attributable to an effect of mites per se, rather than to a character correlated with parasitism or previous parasite infestation.     

DNA Fingerprinting of Individual Species and Intergeneric and Interspecific Hybrids of the Genera Bos and Bison, Subfamily Bovinae

Genome fingerprinting with a hypervariable minisatellite sequence of phage M13 DNA was used to study the genetic variation in individual species of the genera Bosand Bison(subfamily Bovinae) and in their interspecific and intergeneric hybrids. DNA fingerprints were obtained for domestic cow Bos taurus primigenius, vatussy Bos taurus macroceros, banteng Bos javanicus, gaur Bos gaurus, wisent Bison bonasus, bison Bison bison, and for the interspecific and intergeneric hybrids. Compared with the original species, most hybrids showed a greater variation in number and size of hybridization fragments. An association was revealed between the number of hybridization fragments and degree of consanguinity of interspecific hybrids resulting from unique crossing of domestic cow and banteng. Pairwise similarity coefficients were calculated to construct a dendrogram of genetic similarity, which reflected the relationships between the parental species and hybrids varying in degree of consanguinity. The applicability of the method for identifying interspecific and intergeneric hybrids and for studying the consequences of hybridization in the subfamily Bovinae is discussed.     

Abundant variations of <Emphasis Type="Italic">MC4R</Emphasis> gene revealed by Phylogenies of Yak (<Emphasis Type="Italic">Bos grunniens</Emphasis>) and other mammals

MC4R gene was proved to play important roles in body weight regulation in many mammals and exhibit higher homology among different species. The mutations MC4R significantly correlated to the restricted feeding weight, fat deposition and energy balance. In this work, ORF sequences of MC4R gene of Bos grunniens were cloned and phylogenetic relationships of yak and other mammals were analyzed on the basis of MC4R genes. Totally 290 variable sites were examined in 25 sequences from 22 different mammals, and 23 haplotypes were defined with a haplotype diversity of 0.9900. All the sequences were clustered into phylogenetic clades representing different orders or families. The individuals of Bos grunniens, Bos taurus and Ovis aries which belonged to the family of Bovidae were more divergent from the other orders or families and bovid animals may have branched out from the phylogenetic tree earlier than other mammals analyzed during 450 million years of vertebrate evolution. Amino acid sequences inferred from MC4R genes exhibited 54 variable sites, while high conservation of MC4R was observed within the same order or family. We concluded that coding region of MC4R gene displayed abundant variations among different mammal phylogenetic clades, whereas, the conservation of MC4R within order or family could be explained that MC4R gene may have been subjected to substantial constraints or strong purifying selection during several million years of mammal evolution.     

Associations of single nucleotide polymorphisms in candidate genes with the polled trait in Datong domestic yaks

The domestic yak (Bos grunniens) is an iconic symbol of animal husbandry at high altitudes. Yaks exhibit unique external characteristics including long hair and large horns. However, hornless yaks can be found in different breeds and different populations. The hornless trait is also known as polled, and the POLL locus has been fine‐mapped to chromosome 1 in cattle (Bos taurus), although the underlying genetic basis of the polled trait is still unclear in the yak. Thus, we performed an association study to identify the genetic polymorphisms responsible for the polled trait in the yak. Fifty polled Datong domestic yaks and 51 horned individuals were selected randomly from a huge herd and were used as the case and control groups respectively for the association analysis. Twelve genes located in the candidate region of the POLL locus in cattle were used as references to detect DNA polymorphisms related to yak polledness, which were analyzed by sequencing and a high‐resolution melting test. We applied Fisher's exact test and haplotype analysis to show that a 147‐kb segment that included three protein‐coding genes C1H21orf62, GCFC1 and SYNJ1 was the most likely location of the POLL mutation in domestic yaks.     

Post-fire management targeting invasive annual grasses may have inadvertently released the exotic perennial forb Chondrilla juncea and suppressed its biocontrol agent

Top-down and bottom-up factors affecting invasive populations are rarely considered simultaneously, yet their interactive responses to disturbances and management interventions can be essential to understanding invasion patterns. We evaluated post-fire responses of the exotic perennial forb Chondrilla juncea (rush skeletonweed) and its biocontrol agents to landscape factors and a post-fire combined herbicide (imazapic) and bacteria (Pseudomonas fluorescens strain MB906) treatment that targeted invasive annual grasses in a sagebrush steppe ecosystem. Biocontrol agents released against C. juncea in previous decades included Cystiphora schmidti (gall midge), Aceria chondrillae (gall mite), and Puccinia chondrillina (rust fungus). C. juncea abundance was greater in sprayed than unsprayed plots, and where soils were coarser, slopes faced southwest, solar heat loads and topographic water accumulation were greater, and cover of deep-rooted native perennials was lower. Mite infestation was greater in unsprayed plots, midge infestation was greater at higher elevations on steeper slopes, and midges were more abundant while rust was less abundant on gravelly soils. Biocontrol infestation levels varied considerably between years and could not be predicted in 2019 from 2018 infestation levels. Multiple biocontrol species were often present at the same plots but were rarely present on the same C. juncea individuals. These results suggest that spatial patterns of invasion by C. juncea are related to deep-soil water availability, warmer conditions, and alleviation of competition. Treatments designed to reduce invasive annual grasses may inadvertently release C. juncea by both reducing plant competition for soil resources and affecting biocontrol agent (mite) abundance.