Conservation management strategy impacts inbreeding and mutation load in scimitar-horned oryx.

In an age of habitat loss and overexploitation, small populations, both captive and wild, are increasingly facing the effects of isolation and inbreeding. Genetic management has therefore become a vital tool for ensuring population viability. However, little is known about how the type and intensity of intervention shape the genomic landscape of inbreeding and mutation load. We address this using whole-genome sequence data of the scimitar-horned oryx (Oryx dammah), an iconic antelope that has been subject to contrasting management strategies since it was declared extinct in the wild. We show that unmanaged populations are enriched for long runs of homozygosity (ROH) and have significantly higher inbreeding coefficients than managed populations. Additionally, despite the total number of deleterious alleles being similar across management strategies, the burden of homozygous deleterious genotypes was consistently higher in unmanaged groups. These findings emphasize the risks associated with deleterious mutations through multiple generations of inbreeding. As wildlife management strategies continue to diversify, our study reinforces the importance of maintaining genome-wide variation in vulnerable populations and has direct implications for one of the largest reintroduction attempts in the world.

Diagnostic Yield of Colonoscopy in Patients With Symptoms Compatible With Rome IV Functional Bowel Disorders.

BACKGROUND & AIMS: There is little data on the diagnostic yield of colonoscopy in patients with symptoms compatible with functional bowel disorders (FBDs). Previous studies have only focused on diagnostic outcomes of colonoscopy in those with suspected irritable bowel syndrome using historic Rome I-III criteria, whilst having partially assessed for alarm features and shown markedly conflicting results. There is also no colonoscopy outcome data for other FBDs, such as functional constipation or functional diarrhea. Using the contemporaneous Rome IV criteria we determined the diagnostic yield of colonoscopy in patients with symptoms compatible with a FBD, stratified diligently according to the presence or absence of alarm features. METHODS: Basic demographics, alarm features, and bowel symptoms using the Rome IV diagnostic questionnaire were collected prospectively from adults attending out-patient colonoscopy in 2019. Endoscopists were blinded to the questionnaire data. Organic disease was defined as the presence of inflammatory bowel disease, colorectal cancer, or microscopic colitis. RESULTS: 646 patients fulfilled symptom-based criteria for the following Rome IV FBDs: IBS (56%), functional diarrhea (27%) and functional constipation (17%). Almost all had alarm features (98%). The combined prevalence of organic disease was 12%, being lowest for functional constipation and IBS-constipation (∼6% each), followed by IBS-mixed (∼9%), and highest amongst functional diarrhea and IBS-diarrhea (∼17% each); p = .005. The increased prevalence of organic disease in diarrheal versus constipation disorders was accounted for by microscopic colitis (5.7% vs. 0%, p < .001) but not inflammatory bowel disease (7.2% vs. 4.0%, p = .2) or colorectal cancer (4.2% vs. 2.3%, p = .2). However, 1-in-4 chronic diarrhea patients - conceivably at risk for microscopic colitis - did not have colonic biopsies taken. Finally, only 11 of 646 (2%) patients were without alarm features, in whom colonoscopy was normal. CONCLUSIONS: Most patients with symptoms of FBDs who are referred for colonoscopy have alarm features. The presence of organic disease is significantly higher in diarrheal versus constipation disorders, with microscopic colitis largely accounting for the difference whilst also being a missed diagnostic opportunity. In those patients without alarm features, the diagnostic yield of colonoscopy was nil.

Fecal Immunochemical Testing in Patients With Low-Risk Symptoms of Colorectal Cancer: A Diagnostic Accuracy Study.

BACKGROUND: The fecal immunochemical test (FIT) is recommended for triaging primary care patients in England with low-risk symptoms of colorectal cancer (CRC). The evidence underpinning recommendations by the National Institute for Health and Care Excellence had limitations, with a paucity of primary care evidence. This study examines the diagnostic accuracy of FIT in a defined low-risk symptom primary care population. PATIENTS AND METHODS: Consecutive symptomatic adult patients referred for a FIT between October and December 2019 were included. Patients were derived from 225 primary care practices in England. Serious colorectal diseases (CRC, high-risk polyps, and inflammatory bowel disease [IBD]) were identified through patient follow-up over 18 months, using both primary and secondary healthcare records. Performance characteristics of FIT are reported according to differing thresholds, including the currently recommended threshold of ≥10 µg hemoglobin per gram of feces (µg/g). RESULTS: A total of 3,506 patients were included in the final analysis. Of these, 708 had a positive FIT result (≥10 µg/g). The prevalence of CRC was 1.3%. FIT positivity declined from 20.2% to 5.8% and 4.5% at cutoffs of 10, 80, and 120 µg/g, respectively. The sensitivity of FIT at ≥10 µg/g to detect CRC was 91.1% (95% CI, 77.9%-97.1%); its specificity was 80.7% (95% CI, 79.3%-82.0%); the positive predictive value (PPV) was 5.8% (95% CI, 4.2%-7.8%); and the negative predictive value (NPV) was 99.9% (95% CI, 99.6%-99.95%). The area under the receiver operating characteristic curve was 0.93 (0.91-0.96). PPV and specificity increased, whereas sensitivity and NPV decreased when serious colorectal diseases (CRC, high-risk polyps, and IBD) were combined. Age, sex, socioeconomic deprivation, and anemia did not significantly influence FIT sensitivity on subgroup analysis. CONCLUSIONS: Utilization of FIT at a threshold ≥10 µg/g can safely triage patients with low-risk symptoms in primary care, with negative results effectively ruling out CRC.

Position change during colonoscope withdrawal increases polyp and adenoma detection in the right but not in the left side of the colon: results of a randomized controlled trial.

BACKGROUND: It has been suggested that changing patient position during colonoscope withdrawal increases adenoma detection. The results of previous studies have been conflicting. OBJECTIVE: To evaluate whether routine position change during colonoscope withdrawal improves polyp detection. DESIGN: Randomized, 2-way, crossover study. SETTING: Teaching hospital. PATIENTS: A total of 130 patients attending for diagnostic colonoscopy. INTERVENTIONS: Patients undergoing colonoscopy had each colon segment examined twice: the right side of the colon (cecum to hepatic flexure) in the supine and left lateral position and the left side of the colon (splenic flexure and descending colon) in the supine and right lateral position. The transverse colon was examined twice in the supine position. MAIN OUTCOME MEASUREMENTS: The primary outcome measure was the polyp detection rate (≥1 polyp) per colon segment. Secondary outcome measures included the number and proportion of patients with ≥1 adenoma in each segment and adequacy of luminal distension (1 = total collapse and 5 = no collapse). RESULTS: Examination of the right side of the colon in the left lateral position significantly improved polyp detection (26.2% vs 17.7%; P = .01) and luminal distension (mean = 4.0 vs 3.5; P < .0001). Position change did not improve polyp detection in the left side of the colon (5.4% vs 4.6%; P = .99). There was no significant correlation between luminal distension and polyp detection in the right side of the colon (r = .03). LIMITATIONS: Single center and open study design. CONCLUSION: Examining the right side of the colon in the left lateral position increased polyp detection compared with examination in the supine position. Polyp detection in the left side of the colon was similar in the right lateral and supine positions. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01554098.).

A randomized comparison of cold snare polypectomy versus a suction pseudopolyp technique.

BACKGROUND: Cold snare techniques are widely used for removal of diminutive and small colorectal polyps. The influence of resection technique on the effectiveness of polypectomy is unknown. We therefore compared standard cold snare polypectomy with a newly described suction pseudopolyp technique, for completeness of excision and for complications. PATIENTS AND METHODS: In this single-center study, 112 patients were randomized to cold snare polypectomy or the suction pseudopolyp technique. Primary outcome was endoscopic completeness of excision. Consensus regarding the endoscopic assessment of completeness of excision was standardized and aided by chromoendoscopy. Secondary outcomes included: completeness of histological excision, polyp "fly away" and retrieval rates, early bleeding (48 hours), delayed bleeding (2 weeks), and perforation. RESULTS: 148 polyps were removed, with size range 3 - 7 mm, 60 % in the left colon, and 90 % being sessile. Regarding completeness of excision (with uncertain findings omitted): endoscopically, this was higher with the suction pseudopolyp technique compared with cold snare polypectomy but not statistically significantly so (73/74 [98.6 %] vs. 63/68 [92.6 %]; P = 0.08). A trend towards a higher complete histological excision rate with the suction pseudopolyp technique was also not statistically significant (45/59 [76.3 %] vs. 37/58 [63.8 %]; P = 0.14). Polyp retrieval rate was not significantly different (suction 68/76 [89.5 %] vs. cold snare 64/72 [88.9 %]; P = 0.91). No perforation or bleeding requiring hemostasis occurred in either group.  CONCLUSION: In this study both polypectomy techniques were found to be safe and highly effective, but further large multicenter trials are required.Clinical trial registration at www.clinicaltrials.gov: NCT02208401.

Polypectomy practices of sub-centimeter polyps in the English Bowel Cancer Screening Programme.

BACKGROUND: Most colonic polyps are small, and several polypectomy techniques are available. We aimed to describe the variation in polypectomy techniques employed for the removal of sub-centimeter polyps in relation to polyp characteristics, completeness of histological excision and safety. METHODS: Prospectively collected data relating to the removal of sub-centimeter polyps over a 3-year period (between January 2010 and December 2012) were retrieved from the English Bowel Cancer Screening Programme. RESULTS: A total of 147,174 sub-centimeter polyps were removed during 62,679 procedures. For pedunculated polyps, hot snare was most common in the left (median 92 %, IQR 83.3-97.0 %) and right colon (median 75 %, IQR 3-92 %). For non-pedunculated polyps, cold snare was most common in the right colon (median 24 %, IQR 9-47 %); whereas hot snare remained most common in the left colon (median 32 %, IQR 19-49 %). Surgeons were more likely than physicians to use diathermy-assisted techniques (65.6 vs. 56.5 %, p < 0.001). Twelve (0.03 %) bleeding episodes required transfusion with no polypectomy technique dominating and 16 (0.04 %) perforations with 81 % of polypectomies performed using diathermy-assisted techniques. There was substantial variation between screening centers for the completeness of histological excision. For non-pedunculated polyps, histologically confirmed complete excision was more after EMR (23.4 %) compared with other techniques (cold biopsy forceps 17.7 %, cold snare 15.1 %, hot biopsy forceps 19.1 %, hot snare 21.5 %). The use of cold techniques and EMR has increased over time, whereas the use of hot biopsy forceps and hot snare has decreased (p < 0.001). CONCLUSIONS: The removal of sub-centimeter polyps within the BCSP is safe despite wide variations in practice. The use of cold resection techniques and EMR has increased over time. The histological assessment for completeness of excision is limited and should be confirmed endoscopically at the time of polypectomy.

Cold snare polypectomy: does snare type influence outcomes?

BACKGROUND AND AIM: Cold snare techniques are widely used for the removal of small and diminutive polyps. The influence of snare type on the effectiveness of cold snare polypectomy is unknown. METHODS: Cold snare polypectomy of 3-7-mm polyps was undertaken using either a thin wire mini-snare (0.30 mm) or a thick wire mini-snare (0.47 mm). Primary outcome was endoscopic completeness of excision. Consensus regarding endoscopic assessment of completeness of excision was standardized and aided by chromoendoscopy. Secondary outcomes included: completeness of histological excision, polyp 'fly away', polyp retrieval rate, early or delayed bleeding and perforation. RESULTS: One hundred and fifty-seven polyps were removed ranging from 3 to 7 mm, 62% were situated in the left side of the colon and 89.4% were sessile. Endoscopic completeness of excision was significantly higher with the thin wire snare compared to the thick wire snare (90.2% vs 73.3%, P < 0.05). There was a numerical trend towards a higher complete histological excision rate with the thin wire snare, but this did not reach statistical significance (73.3% vs 65.2%, P = 0.4). There was a fair level of agreement (kappa = 0.36) between endoscopic and histological completeness of excision. Polyp 'fly away' occurred less often with the thin wire snare (14.6% vs 35.3%, P = 0.002), but there was no significant difference in polyp retrieval rate (84.3% vs 83.8%, P = 0.94). There were no complications with either snare. CONCLUSION: Snare type appears to be an important determinant of completeness of excision when removing small polyps by the cold snare technique.

The genome sequence of the Western Capercaillie Tetrao urogallus Linnaeus, 1758.

We present a genome assembly from an individual male Tetrao urogallus (the Western Capercaillie; Chordata; Aves; Galliformes; Phasianidae). The genome sequence is 1,013.2 megabases in length. Most of the assembly is scaffolded into 39 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 16.68 kilobases in length.

Rejection of Fecal Immunochemical Tests Within the Lower Gastrointestinal Diagnostic Pathway: A Cohort Study.

INTRODUCTION/OBJECTIVES: The fecal immunochemical test (FIT) helps triage primary care patients at risk of colorectal cancer (CRC). Improving FIT returns has received recent attention, however uncertainty exists regarding the accurate completion of samples provided for laboratory analysis. This study aims to identify the rejection rate of returned FIT samples and determine rejection causes. METHODS: FIT samples from symptomatic patients within South Yorkshire, Bassetlaw, and North Derbyshire are processed at a central laboratory. Tests requests are made from 225 GP practices, which serve an estimated 2 million population. This study describes a retrospective review of FIT samples received in the central laboratory between 01/09/19 and 31/12/22. Locally held data was interrogated in March 2023 to determine the number of FIT samples received and rejected during the study period. Documented reasons for rejection were explored to identify common themes. RESULTS: Total FIT specimens received during the study period was 126 422. Of these, 5190 (4.1%) were rejected. Monthly rejection rates fell from 17.4% in September 2019 to 1.3% in December 2022 (P < .001). Sampling errors were the most frequent cause for FIT rejection (2151/5190), with other causes including: expired specimen; no sample collection date/ time, no request form, incomplete patient information and illegible handwriting. CONCLUSIONS: This is the first study exploring FIT rejection rates in symptomatic primary care patients, which shows improvements in rejection rates over time. Targeted interventions could improve rejection rates further, thereby reducing NHS resource use and costs and diagnostic delays.

Demographic and conservation genomic assessment of the threatened marbled teal (Marmaronetta angustirostris).

Genetic assessment of species that have experienced dramatic population declines provides critical information that is instrumental for the design of conservation recovery programs. Here, we use different sources of molecular data (mtDNA and ddRAD-seq) to evaluate the genetic status of wild and captive populations of marbled teal (Marmaronetta angustirostris), a duck species classified as critically endangered in Spain and near threatened at a global scale. First, we determined the evolutionary and demographic trajectories of the wild population from Spain and the currently much larger population from Iraq, which is also the documented source of European zoo stocks. Second, we evaluated the suitability of the different captive populations for ongoing restocking programs in Spain and assessed their potential impact on the genetic composition of wild populations. Populations from Spain and Iraq were assigned to distinct genetic clusters, albeit with an overall low level of genetic differentiation, in line with their recent divergence (<8000 years ago) and lack of phylogeographic structure in the species. Demogenomic inferences revealed that the two populations have experienced parallel demographic trajectories, with a marked bottleneck during the last glacial period followed by a sudden demographic expansion and stability since the onset of the Holocene. The wild population from Spain presented high levels of inbreeding, but we found no evidence of recent genetic bottlenecks compatible with the human-driven decline of the species during the past century. The captive populations from the two Spanish centers involved in restocking programs showed genetic introgression from European zoos; however, we found limited evidence of introgression from the zoo genetic stock into the wild population from Spain, suggesting captive-bred birds have limited breeding success in the wild. Our study illustrates how ex situ conservation programs should consider the genetic distinctiveness of populations when establishing breeding stocks and highlights the importance of genetically assessing captive populations prior to reinforcement actions.

The genetic legacy of the first successful reintroduction of a mammal to Britain: Founder events and attempted genetic rescue in Scotland's beaver population.

Conservation translocations often inherently involve a risk of genetic diversity loss, and thus loss of adaptive potential, but this risk is rarely quantified or monitored through time. The reintroduction of beavers to Scotland, via the Scottish Beaver Trial in Knapdale, is an example of a translocation that took place in the absence of genetic data for the founder individuals and resulted in a small and suspected to be genetically depauperate population. In this study we use a high-density SNP panel to assess the genetic impact of that initial translocation and the effect of subsequent reinforcement translocations using animals from a different genetic source to the original founders. We demonstrate that the initial translocation did, indeed, lead to low genetic diversity (H o = 0.052) and high mean kinship (KING-robust = 0.159) in the Knapdale population compared to other beaver populations. We also show that the reinforcement translocations have succeeded in increasing genetic diversity (H o = 0.196) and reducing kinship (KING robust = 0.028) in Knapdale. As yet, there is no evidence of admixture between the two genetic lineages that are now present in Knapdale and such admixture is necessary to realise the full genetic benefits of the reinforcement and for genetic reinforcement and then rescue to occur; future genetic monitoring will be required to assess whether this has happened. We note that, should admixture occur, the Knapdale population will harbour combinations of genetic diversity not currently seen elsewhere in Eurasian beavers, posing important considerations for the future management of this population. We consider our results in the wider context of beaver conservation throughout Scotland and the rest of Britain, and advocate for more proactive genetic sampling of all founders to allow the full integration of genetic data into translocation planning in general.

Genome mapping in intensively studied wild vertebrate populations.

Over the past decade, long-term studies of vertebrate populations have been the focus of many quantitative genetic studies. As a result, we have a clearer understanding of why some fitness-related traits are heritable and under selection, but are apparently not evolving. An exciting extension of this work is to identify the genes underlying phenotypic variation in natural populations. The advent of next-generation sequencing and high-throughput single nucleotide polymorphism (SNP) genotyping platforms means that mapping studies are set to become widespread in those wild populations for whom appropriate phenotypic data and DNA samples are available. Here, we highlight the progress made in this area and define evolutionary genetic questions that have become tractable with the arrival of these new genomics technologies.

Resumption of Antiplatelet Therapy after Major Bleeding.

Major bleeding is a common threat in patients requiring antiplatelet therapy. Timing and intensity with regard to resumption of antiplatelet therapy represent a major challenge in clinical practice. Knowledge of the patient's bleeding risk, defining transient/treatable and permanent/untreatable risk factors for bleeding, and weighing these against thrombotic risk are key to successful prevention of major adverse events. Shared decision-making involving various disciplines is essential to determine the optimal strategy. The present article addresses clinically relevant questions focusing on the most life-threatening or frequently occurring bleeding events, such as intracranial hemorrhage and gastrointestinal bleeding, and discusses the evidence for antiplatelet therapy resumption using individual risk assessment in high-risk cardiovascular disease patients.

Genetic diversity in global populations of the critically endangered addax (Addax nasomaculatus) and its implications for conservation.

Threatened species are frequently patchily distributed across small wild populations, ex situ populations managed with varying levels of intensity and reintroduced populations. Best practice advocates for integrated management across in situ and ex situ populations. Wild addax (Addax nasomaculatus) now number fewer than 100 individuals, yet 1000 of addax remain in ex situ populations, which can provide addax for reintroductions, as has been the case in Tunisia since the mid-1980s. However, integrated management requires genetic data to ascertain the relationships between wild and ex situ populations that have incomplete knowledge of founder origins, management histories, and pedigrees. We undertook a global assessment of genetic diversity across wild, ex situ and reintroduced populations in Tunisia to assist conservation planning for this Critically Endangered species. We show that the remnant wild populations retain more mitochondrial haplotypes that are more diverse than the entirety of the ex situ populations across Europe, North America and the United Arab Emirates, and the reintroduced Tunisian population. Additionally, 1704 SNPs revealed that whilst population structure within the ex situ population is minimal, each population carries unique diversity. Finally, we show that careful selection of founders and subsequent genetic management is vital to ensure genetic diversity is provided to, and minimize drift and inbreeding within reintroductions. Our results highlight a vital need to conserve the last remaining wild addax population, and we provide a genetic foundation for determining integrated conservation strategies to prevent extinction and optimize future reintroductions.

Prioritisation of lower gastrointestinal endoscopy during the COVID-19 pandemic: outcomes of a novel triage pathway.

Objective: The 2-week-wait (2ww) referral pathway is used in England to fast-track patients with suspected colorectal cancer (CRC). A two-stage triage pathway was used to prioritise lower gastrointestinal (LGI) endoscopy for suspected CRC during the COVID-19 pandemic. Method: All patients referred for an LGI endoscopy via a 2ww referral pathway between March 2020 and July 2020 were assessed. The first stage triaged patients to high, standard or low risk of CRC based on symptoms and faecal immunochemical test (FIT), and offered CT scans to those at high risk. The second stage, endoscopy prioritisation (EP), incorporated the CT results, FIT and symptoms to triage into four groups, EP1-EP4; with EP1 being the most urgent and EP4 the least. The primary outcome measure was CRC detection. Results: 514 patients were included. The risk of CRC was triaged as high in 190/514 patients (37%), standard in 274/514 patients (53%) and low in 50/514 (10%) patients. 422/514 patients (82%) underwent endoscopy with triage to EP1 in 52/422 (12%), EP2 in 105/422 (25%), EP3 in 210/422 (50%) and EP4 in 55/422 (13%). CRC was detected in 23 patients (5.4%). CRC was significantly more frequent in the EP1 group (23.1%, relative risk (RR)=16.2) and EP2 group (6.7%, RR=4.7) compared with EP3 group (1.4%). All CRC lesions were identified by CT imaging when performed prior to LGI endoscopy. Conclusion: This triage pathway designated 83% of patients with CRC to either EP1 or EP2. During a period of limited endoscopy provision, this pathway effectively prioritises endoscopy for those at greatest risk of CRC.

Genetic mapping of the major histocompatibility complex in the zebra finch (Taeniopygia guttata).

Genes of the major histocompatibility complex (MHC) have received much attention in immunology, genetics, and ecology because they are highly polymorphic and play important roles in parasite resistance and mate choice. Until recently, the MHC of passerine birds was not well-described. However, the genome sequencing of the zebra finch (Taeniopygia guttata) has partially redressed this gap in our knowledge of avian MHC genes. Here, we contribute further to the understanding of the zebra finch MHC organization by mapping SNPs within or close to known MHC genes in the zebra finch genome. MHC class I and IIB genes were both mapped to zebra finch chromosome 16, and there was no evidence that MHC class I genes are located on chromosome 22 (as suggested by the genome assembly). We confirm the location in the MHC region on chromosome 16 for several other genes (BRD2, FLOT1, TRIM7.2, GNB2L1, and CSNK2B). Two of these (CSNK2B and FLOT1) have not previously been mapped in any other bird species. In line with previous results, we also find that orthologs to the immune-related genes B-NK and CLEC2D, which are part of the MHC region in chicken, are situated on zebra finch chromosome Z and not among other MHC genes in the zebra finch.

Increased psychological distress and somatization in patients with irritable bowel syndrome compared with functional diarrhea or functional constipation, based on Rome IV criteria.

BACKGROUND: The Rome IV criteria for disorders of gut-brain interaction define irritable bowel syndrome (IBS) as a functional bowel disorder associated with frequent abdominal pain of at least 1 day per week. In contrast, functional diarrhea (FD) and functional constipation (FC) are relatively painless. We compared differences in mood and somatization between Rome IV IBS and FC/FD. METHODS: A total of 567 patients with Rome IV defined IBS or FD/FC completed a baseline questionnaire on demographics, abdominal pain frequency, mood (hospital anxiety and depression scale, HADS), and somatization (patient health questionnaire, PHQ-12). The primary analysis compared differences in mood and somatization between IBS and FC/FD, and the relative influence of abdominal pain frequency on these extra-intestinal symptoms. The secondary analysis evaluated differences across individual IBS subtypes, and also between FC and FD. KEY RESULTS: Patients with IBS-in comparison to those with FC/FD-had significantly higher mean PHQ-12 somatization scores (9.1 vs. 5.4), more somatic symptoms (6.0 vs. 4.3), abnormally high somatization levels (16% vs. 3%), higher HADS score (15.0 vs. 11.7), and clinically abnormal levels of anxiety (38% vs. 20%) and depression (17% vs. 10%). Increasing abdominal pain frequency correlated positively with PHQ-12, number of somatic symptoms, and HADS; p < 0.001. No differences in mood and somatization scores were seen between individual IBS subtypes, and nor between FC and FD. CONCLUSION & INFERENCES: Based on the Rome IV criteria, IBS is associated with increased levels of psychological distress and somatization compared with FD or FC. Patients reporting frequent abdominal pain should be comprehensively screened for psychosomatic disorders, with psychological therapies considered early in the disease course.

Genetic diversity of the Nubian ibex in Oman as revealed by mitochondrial DNA.

The Nubian ibex (Capra nubiana) is patchily distributed across parts of Africa and Arabia. In Oman, it is one of the few free-ranging wild mammals found in the central and southern regions. Its population is declining due to habitat degradation, human expansion, poaching and fragmentation. Here, we investigated the population's genetic diversity using mitochondrial DNA (D-loop 186 bp and cytochrome b 487 bp). We found that the Nubian ibex in the southern region of Oman was more diverse (D-loop HD; 0.838) compared with the central region (0.511) and gene flow between them was restricted. We compared the genetic profiles of wild Nubian ibex from Oman with captive ibex. A Bayesian phylogenetic tree showed that wild Nubian ibex form a distinct clade independent from captive animals. This divergence was supported by high mean distances (D-loop 0.126, cytochrome b 0.0528) and high F ST statistics (D-loop 0.725, cytochrome b 0.968). These results indicate that captive ibex are highly unlikely to have originated from the wild population in Oman and the considerable divergence suggests that the wild population in Oman should be treated as a distinct taxonomic unit. Further nuclear genetic work will be required to fully elucidate the degree of global taxonomic divergence of Nubian ibex populations.

Understanding the impact of sire lean meat yield breeding value on carcass composition, meat quality, nutrient and mineral content of Australian lamb.

Advances in genomics and technology measuring body composition are now allowing sheep producers to select directly for increased lean meat yield (LMY) using Australian Sheep Breeding Values (ASBV). This experiment evaluated the impact of sire LMY ASBV on carcass composition, meat quality, nutrient and mineral content for lambs reared at pasture and finished in a feedlot. A 1% unit increase in sire LMY ASBV resulted in progeny that were leaner (0.8%) and had less fat (1.0%) on carcass. There was also a 0.2% reduction in the intramuscular fat content, a 3.2 N increase in meat toughness determined by shear force at day 5 ageing, a reduction in the redness of the fresh meat and a lower iron content. It is concluded that Australian sheep producers will need to incorporate ASBVs for other aspects of meat quality when selecting sires with increased LMY to avoid deterioration in meat quality, nutritional content of lamb and fresh meat colour.