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Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species’ range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the “restocking from the wild” hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments.

Yellow fever (YF) causes severe morbidity and mortality in Africa and South America. It is an arthropod-borne viral disease endemic to tropical regions of Africa and South America. Yellow fever virus (YFV) is transmitted by mosquitoes and frequently affects both non-human primates (NHPs) and humans. Neotropical primates (NTPs) are generally more severely afflicted by YFV than African primates. Asian primates appear not to be susceptible to this disease. Susceptibility varies among NTP species: asymptomatic infections are described in some NTP species, whereas severe epizootic mortality events are described in others. The genus Alouatta (howler monkeys) is considered to be the most susceptible among the NTPs. Epizootic events resulting in the death of thousands of NTPs have been recorded in recent history. As a result, YFV poses a threat to the survival of some NTP species. In most cases, NTPs are found dead without showing prior clinical signs. In cases where clinical signs are observed, they are mostly non-specific. Due to their high susceptibility, epizootic events in NTPs are used as epidemiological predictors for human YF outbreaks. YFV infection may be diagnosed by means of virus isolation, reverse transcription polymerase chain reaction, serology, histopathology, or immunohistochemistry. Animals that survive the disease develop neutralizing antibodies to YFV. Currently, no specific treatment is available. Sustained YF control strategies must rely on surveillance and accurate diagnostics to allow for early detection of outbreaks and rapid implementation of control measures. Prophylaxis should be based on a One Health perspective that recognizes the intricate interplay between human health, primate health, and the environment. Vaccines for YF are available, with the human 17DD vaccine effectively preventing disease in primates. However, mitigation strategies continue to rely more and more on vector control, preferably using eco-friendly methods. Climate change and human activities, and their impact on local ecology, are assumed to increase the risk of YF transmission in the next decades.

Background Cattle are considered to be the most desirable livestock by small scale farmers. In Africa, although comprehensive genomic studies have been carried out on cattle, the genetic variations in indigenous cattle from Nigeria have not been fully explored. In this study, genome-wide analysis based on genotyping-by-sequencing (GBS) of 193 Nigerian cattle was used to reveal new insights on the history of West African cattle and their adaptation to the tropical African environment, particularly in sub-Saharan region.  Results The GBS data were evaluated against whole-genome sequencing (WGS) data and high rate of variant concordance between the two platforms was evident with high correlated genetic distance matrices genotyped by both methods suggestive of the reliability of GBS applicability in population genetics. The genetic structure of Nigerian cattle was observed to be homogenous and unique from other African cattle populations. Selection analysis for the genomic regions harboring imprints of adaptation revealed genes associated with immune responses, growth and reproduction, efficiency of feeds utilization, and heat tolerance. Our findings depict potential convergent adaptation between African cattle, dogs and humans with adaptive genes SPRY2 and ITGB1BP1 possibly involved in common physiological activities. Conclusion The study presents unique genetic patterns of Nigerian cattle which provide new insights on the history of cattle in West Africa based on their population structure and the possibility of parallel adaptation between African cattle, dogs and humans in Africa which require further investigations.

Background Prion diseases, also known as transmissible spongiform encephalopathies (TSEs) remain one of the deleterious disorders, which have affected several animal species. Polymorphism of the prion protein ( PRNP ) gene majorly determines the susceptibility of animals to TSEs. However, only limited studies have examined the variation in PRNP gene in different Nigerian livestock species. Thus, this study aimed to identify the polymorphism of PRNP gene in Nigerian livestock species (including camel, dog, horse, goat, and sheep). We sequenced the open reading frame (ORF) of 65 camels, 31 village dogs and 12 horses from Nigeria and compared with PRNP sequences of 886 individuals retrieved from public databases. Results All the 994 individuals were assigned into 162 haplotypes. The sheep had the highest number of haplotypes ( n  = 54), and the camel had the lowest ( n  = 7). Phylogenetic tree further confirmed clustering of Nigerian individuals into their various species. We detected five non-synonymous SNPs of PRNP comprising of G9A, G10A, C11G, G12C, and T669C shared by all Nigerian livestock species and were in Hardy-Weinberg Equilibrium (HWE). The amino acid changes in these five non-synonymous SNP were all “benign” via Polyphen-2 program. Three SNPs G34C, T699C, and C738G occurred only in Nigerian dogs while C16G, G502A, G503A, and C681A in Nigerian horse. In addition, C50T was detected only in goats and sheep. Conclusion Our study serves as the first to simultaneously investigate the polymorphism of PRNP gene in Nigerian livestock species and provides relevant information that could be adopted in programs targeted at breeding for prion diseases resistance.

Prion diseases, also known as transmissible spongiform encephalopathies (TSEs) remain one of the deleterious disorders, which have affected several animal species. Polymorphism of the prion protein (PRNP) gene majorly determines the susceptibility of animals to TSEs. However, only limited studies have examined the variation in PRNP gene in different Nigerian livestock species. Thus, this study aimed to identify the polymorphism of PRNP gene in Nigerian livestock species (including camel, dog, horse, goat, and sheep). We sequenced the open reading frame (ORF) of 65 camels, 31 village dogs and 12 horses from Nigeria and compared with PRNP sequences of 886 individuals retrieved from public databases. All the 994 individuals were assigned into 162 haplotypes. The sheep had the highest number of haplotypes (n = 54), and the camel had the lowest (n = 7). Phylogenetic tree further confirmed clustering of Nigerian individuals into their various species. We detected five non-synonymous SNPs of PRNP comprising of G9A, G10A, C11G, G12C, and T669C shared by all Nigerian livestock species and were in Hardy-Weinberg Equilibrium (HWE). The amino acid changes in these five non-synonymous SNP were all \"benign\" via Polyphen-2 program. Three SNPs G34C, T699C, and C738G occurred only in Nigerian dogs while C16G, G502A, G503A, and C681A in Nigerian horse. In addition, C50T was detected only in goats and sheep. Our study serves as the first to simultaneously investigate the polymorphism of PRNP gene in Nigerian livestock species and provides relevant information that could be adopted in programs targeted at breeding for prion diseases resistance.

The African cattle provide unique genetic resources shaped up by both diverse tropical environmental conditions and human activities, the assessment of their genetic diversity will shade light on the mechanism of their remarkable adaptive capacities. We therefore analyzed the genetic diversity of cattle samples from Nigeria using both maternal and paternal DNA markers. Nigerian cattle can be assigned to 80 haplotypes based on the mitochondrial DNA (mtDNA) D-loop sequences and haplotype diversity was 0.985 + 0.005. The network showed two major matrilineal clustering: the dominant cluster constituting the Nigerian cattle together with other African cattle while the other clustered Eurasian cattle. Paternal analysis indicates only zebu haplogroup in Nigerian cattle with high genetic diversity 1.000 ± 0.016 compared to other cattle. There was no signal of maternal genetic structure in Nigerian cattle population, which may suggest an extensive genetic intermixing within the country. The absence of Bos indicus maternal signal in Nigerian cattle is attributable to vulnerability bottleneck of mtDNA lineages and concordance with the view of male zebu genetic introgression in African cattle. Our study shades light on the current genetic diversity in Nigerian cattle and population history in West Africa.

The genus Scomberomorus , with 18 nominal species, sustains a significant heterogeneous fishery throughout its range. The sole molecular systematic study of this genus concerned the species group S. regalis , which contains the new world taxa. The species diversity of Scomberomorus in the northern Indian Ocean has not been studied at the molecular level, often leading to misidentifications. Here, novel genetic data are provided that reconfigure species boundaries from the region. We used single and multilocus data (eight mitochondrial and three nuclear genes) to infer phylogenetic relationships, species delimitation, and the resurrection of a time-calibrated phylogenetic tree. Our aim was also to verify the hypothesis of geographical races in S. guttatus predicated on variable vertebral counts. Interestingly, all species delimitation analyses have recovered another highly cryptic species in the nominal S. guttatus previously believed to have an Indo-Pacific distribution . Scomberomorus guttatus (Bloch and Schneider, 1801) in the sensu stricto , is redeemed from its type locality based on genetic data and preliminary morphomeristic investigations and has a restricted distribution in the Bay of Bengal. The cryptic species Scomberomorus aff. guttatus which exhibits >10% genetic divergence from S. guttatus is resurrected here from the synonymy of the latter as Scomberomorus leopardus (Shaw, 1803). Widespread in the Indo-Pacific, this species contains two major molecular operational taxonomic units (MOTUs) with a divergence threshold of over 2% between them. Our analysis suggests that vertebral counts must be coupled with other features to identify the species/lineages in the nominal S. guttatus. The heterogeneity in the S. guttatus species group is discussed in relation to the ecological diversity of the region which facilitates larval recruitment and niche specialization. The results also revealed two allopatric putative species in S. commerson , found primarily in the Pacific and Indian Oceans. This study added genetic data from S. lineolatus and S. koreanus , not previously represented in the sequence repositories. Estimation of divergence time indicated that the Indo-West Pacific species group undergoes multiple diversification events besides the recent splits detected within S . leopardus .

This investigation comprises three trials. Trial 1 consists of an in vitro comparison of three semen extenders: two egg yolk based (customized Tris-egg yolk-glycerol and Triladyl®), the third (AndroMed®) soybean lecithin based. With regard to post-thaw motility, the phytoextender AndroMed® proved to be superior (59±3% v. 53±2% and 53±2%, P<0.05). It had earlier been shown that addition of the commercial prostaglandin F2α preparation Dinolytic® before freezing compromises post-thaw motility; therefore, in Trial 2, Dinolytic® was added after thawing. Frozen-thawed spermatozoa tolerated addition of Dinolytic® at a concentration of 30% (v/v). In Trial 3, cows were inseminated using straws in which diluted semen and Dinolytic® were frozen in the same straw, separated by an air bubble, so intermingling could only take place in the course of insemination. Pregnancy rates at Dinolytic® dosages of 0%, 30% or 60% amounted to 44%, 41% and 56%, respectively (P>0.05), a result that encourages a large-scale field study, which is envisioned.

Length - weight relationships (LWRs) were estimated for 50 fish species belonging to 14 families from Indian waters. During the fishery surveys, specimens were collected from various fishing gears such as ring seines, gill nets, trawls and long lines between 2015 and 2017. The number of specimens measured varied by species. All the values of the parameter b were found within the expected range of 2.5 – 3.5. The b values in the relationships, W = aL b varied between 2.562 ( Stolephorus insularis ) and 3.461 ( Auxis thazard ) with mean value of 3.032 (SE = ± 0.029). The LWRs of all the 50 fish species estimated in this study were highly significant ( p  < 0.001, r 2  ≥ 0.850). The study provides the first estimate of LWRs for Scomber indicus , Sphyraena arabiansis and Upeneus margarethae , and complements the existing LWRs in the international literature and FishBase database. In addition, this study reports the new maximum size for Nematalosa nasus (28.5 cm TL, 281 g TW), Scomberoides commersonnianus (122 cm TL, 11400.5 g TW), Scomberoides tol (56 cm TL, 1000 g TW), Alepes djedaba (33.5 cm TL, 343.8 g TW) and Upeneus margarethae (19 cm TL, 87 g TW). This study provides basic biological information in the form of a length-weight key for 50 commercially important fish species from Indian waters as a valuable tool to assist fishery managers.

Summary The present study reports the length‐weight relationships (LWRs) of two clupeoid fish species, Thryssa malabarica (Bloch, 1795) and Thryssa dayi Wongratana, 1983 from Kerala waters, southwest coast of India during the period October 2015 to September 2016. Altogether 88 specimens of T. malabarica and 97 T. dayi were collected on weekly basis from gill nets (mesh size, 2.6–5.0 cm) and ring seines (mesh size, 0.8–2.6 cm) during the period. The value of parameter b in the equation of LWRs was estimated as 3.237 and 3.248 for T. malabarica and T. dayi respectively.