SNP g.1007A>G within the porcine DNAL4 gene affects sperm motility traits and percentage of midpiece abnormalities

The flagellar beating of a spermatozoa's axoneme is caused by the varying activation and inactivation of dynein molecules. Dynein, axonemal, light chain 4 (DNAL 4 ) is a functional candidate gene for sperm motility as it encodes a small subunit of the dyneins. We resequenced the porcine DNAL 4 using three artificial insemination (AI ) boars each with high (>68%) or low (<60%) motility, and detected 23 SNP . These were then genotyped for 82 AI boars. Using spermatological records, significantly negative genetic correlations between ejaculate volume (VOL ) and the further spermatological parameters concentration (CONC ) (r  = ?.43), motility of undiluted semen (MOTUD ) (r  = ?.09), motility after 24 h (MOT 1) (r  = ?.17) and after 48 hr (MOT 2) (r  = ?.23) were estimated. Significantly positive correlations existed between CONC and MOT 1 (r  = .07) as well as MOT 2 (r  = .10), between MOTUD and MOT 1 (r  = .33), between MOTUD and MOT 2 (r  = .36), and finally between MOT 1 and MOT 2 (r  = .70). Significantly negatively correlated were all motility traits with the parameters abnormal acrosome (AA ) (MOTUD r  = ?.06; MOT 1 r  = ?.08, and MOT 2 r  = ?.1) and presence of cytoplasmic droplet (CD ) (MOTUD r  = ?.07; MOT 1 r  = ?.08; MOT 2 r  = ?.07). Association analyses (single marker regression model; SMR ) propose that SNP g.1007A>G, located in the second intron, reduces motility significantly (MOTUD ‐4.59%; MOT 1 ‐10.33%; MOT 2 ‐19.37%). According to the dominant‐recessive model (DRM ), genotype AA is always superior compared to genotypes AG and GG (i.e. MOTUD 67.67%, 64.16% and 53.91%; MOT 1 54.17%, 43.75% and 28.44%; MOT 2 44.12%, 24.91% and 4.97%). The average effect of gene substitution (g.1007A>G) on abnormal midpiece (AM ) was 0.71%, the genotypic values—as expressed by LS means—were 0.1 (AA ) and 0.81 (AG ).     

Qualitative and quantitative ultrasound attributes of maternal‐foetal structures in pregnant ewes

The aim of this study was to examine foetal organs and placental tissue to establish a correlation between the changes in the composition of these structures associated with their maturation and the ultrasonographic characteristics of the images. Twenty‐four pregnant ewes were included in the study. Ultrasonography assessments were performed in B‐mode, from the ninth gestational week until parturition. The lungs, liver and kidneys of foetuses and placentomes were located in transverse and longitudinal sections to evaluate the echogenicity (hypoechoic, isoechoic, hyperechoic or mixed) and echotexture (homogeneous and heterogeneous) of the tissues of interest. For quantitative evaluation of the ultrasonographic characteristics, it was performed a computerized image analysis using a commercial software (Image ProPlus^®). Mean numerical pixel values (NPVs), pixel heterogeneity (standard deviation of NPVs) and minimum and maximum pixel values were measured by selecting five circular regions of interest in each assessed tissue. All evaluated tissues presented significant variations in the NPVs, except for the liver. Pulmonary NPVmean, NPVmin and NPVmax decreased gradually through gestational weeks. The renal parameters gradually decreased with the advancement of the gestational weeks until the 17th week and later stabilized. The placentome NPVmean, NPVmin and NPVmax decreased gradually over the course of weeks. The hepatic tissue did not show echogenicity and echotexture variations and presented medium echogenicity and homogeneous echotexture throughout the experimental period. It was concluded that pixels numerical evaluation of maternal‐foetal tissues was applicable and allowed the identification of quantitative ultrasonographic characteristics showing changes in echogenicity related to gestational age.     

Factors affecting the breeding success of the African Black Oystercatcher (Haematopus moquini): a perspective on protection and food availability

Breeding success (fledglings pair^?1 y^?1) of the Red-listed African Black Oystercatcher (Haematopus moquini) is highly variable, both spatially and temporally. Despite a diversity of natural factors causing this variability, there is evidence that two anthropogenic factors, i.e. disturbance and an introduced mussel (Mytilus galloprovincialis), are having an impact on the local breeding success of this species. Using a data set comprising 87 site-years of nest-monitoring data across most of the species’ breeding range, we analysed the extent and causes of variability in breeding success. Breeding success differed across three population categories defined by varying levels of human disturbance: island populations, protected mainland populations, and unprotected mainland populations. Differences in breeding success between island populations and protected mainland populations were likely due to differing exposure to predators; however, differences between protected and unprotected mainland populations were unlikely caused by this as both experience equivalent predation levels (although from different predators). Protection only improved the breeding success of oystercatchers in very high-quality habitats (with a high biomass of alien mussels), and where populations were ‘released’ from high levels of human disturbance. In unprotected mainland areas, human activity impacted on the breeding success of local populations primarily through predation of small chicks by uncontrolled dogs, and by rising tides drowning chicks that were hiding from human disturbance. The findings of this study note the potential conservation dilemma resulting from an invasive species improving the conservation status of a Red-listed species, and encourage the implementation of restricted sites in high-quality habitats with high breeding pair densities.     

Epidemic of blindness in kangaroos - evidence of a viral aetiology

OBJECTIVE: To determine the cause of an epidemic of blindness in kangaroos. DESIGN AND PROCEDURES: Laboratory examinations were made of eyes and brains of a large number of kangaroos using serological, virological, histopathological, electron microscopical, immunohistochemical methods, and PCR with cDNA sequencing. In addition, potential insect viral vectors identified during the disease outbreak were examined for specific viral genomic sequences. SAMPLE POPULATION: For histopathological analysis, 55 apparently blind and 18 apparently normal wild kangaroos and wallabies were obtained from New South Wales, Victoria, South Australia, and Western Australia. A total of 437 wild kangaroos and wallabies (including 23 animals with apparent blindness) were examined serologically. RESULTS: Orbiviruses of the Wallal and Warrego serogroups were isolated from kangaroos affected with blindness in a major epidemic in south-eastern Australia in 1994 and 1995 and extending to Western Australia in 1995/96. Histopathological examinations showed severe degeneration and inflammation in the eyes, and mild inflammation in the brains. In affected retinas, Wallal virus antigen was detected by immunohistochemical analysis and orbiviruses were seen in electron microscopy. There was serological variation in the newly isolated Wallal virus from archival Wallal virus that had been isolated in northern Australia. There were also variations of up to 20% in genotype sequence from the reference archival virus. Polymerase chain reactions showed that Wallal virus was present during the epidemic in three species of midges, Culicoides austropalpalis, C dycei and C marksi. Wallal virus nucleic acid was also detected by PCR in a paraffin-embedded retina taken from a blind kangaroo in 1975. CONCLUSION: Wallal virus and perhaps also Warrego virus are the cause of the outbreak of blindness in kangaroos. Other viruses may also be involved, but the evidence in this paper indicates a variant of Wallal virus, an orbivirus transmitted by midges, has the strongest aetiological association, and immunohistochemical analysis implicates it as the most damaging factor in the affected eyes.     

Dothistromin toxin is a virulence factor in dothistroma needle blight of pines

Dothistromin is a broad‐spectrum mycotoxin produced by the Dothideomycete pine needle pathogen Dothistroma septosporum. It accumulates in lesions, causing characteristic red bands on needles infected with this fungus. Dothistromin is similar in structure to the aflatoxin precursor versicolorin B and the biosynthetic pathways of these toxins share many common gene products. Although dothistromin is not essential for pathogenicity in dothistroma needle blight, its presence in infected needles suggests it might have a role in the disease process. The hypothesis that dothistromin is a virulence factor was tested by studying Pinus radiata infected with dothistromin‐deficient mutants of D. septosporum. The mutants were able to infect pine needles and complete their life cycle as previously shown, and were unaffected in spore germination, epiphytic growth or needle penetration. However, colonization of the mesophyll by the mutants was restricted compared to the wild type. Correspondingly, lesions produced by the mutants were smaller and produced significantly fewer spores than lesions produced by wildtype strains. Interestingly, ‘green islands’, in which chlorophyll was maintained at a higher level than in adjacent chlorotic and necrotic regions, surrounded early‐appearing lesions caused by both wildtype and mutant strains. At a later stage of disease development green islands were still present in the mutant but appeared to be masked by the extended dothistromin‐containing lesions in the wild type. Overall the results support a role for dothistromin in virulence in dothistroma needle blight.     

Interactions Among Different Devices and Electrical Stimulus on the Electroejaculation of Captive Agoutis (Dasyprocta leporina)

The interactions among different electroejaculation devices associated with serial or continuous stimuli were investigated to improve the efficiency of the electroejaculation for semen collection in agoutis. Ten sexually matured male Dasyprocta leporina were restrained by the intramuscular administration of xylazine–ketamine association. Each individual was randomly subjected to four electroejaculation protocols, by combining two devices (one presenting longitudinal electrodes emitting square waves and other presenting ring electrodes emitting sine waves) and two electrical stimuli protocols (serial or continuous). A total of 40 attempts for electroejaculation were conducted in agoutis, being 10 per treatment. The most efficient treatment in providing ejaculates containing sperm (p < 0.05) was that using and electroejaculator connected to a probe with ring electrodes and associated with serial stimuli (4/7; 57%). In spite of semen parameters obtained by sine waves were adequate for using the samples for assisted reproduction, higher values for sperm motility and functional membrane integrity were obtained in the use of the square wave, independently of the electric stimulation protocol used (p < 0.05). In conclusion, we verified that the use of a device presenting a probe with ring electrodes and emitting sine waves, associated with a serial stimuli protocol, improves the efficiency for semen obtaining by electroejaculation in adults D. leporina.     

Susceptibility of native New Zealand Myrtaceae to the South African strain of Austropuccinia psidii: A biosecurity threat

Austropuccinia psidii, cause of myrtle rust, has spread globally where Myrtaceae occur. Multiple strains of A. psidii have been identified, including a unique strain found only in South Africa. The South African strain is a biosecurity concern for species of Myrtaceae worldwide. This is because preliminary testing of South African Myrtaceae suggests it could have a wide host range, and thus has the potential to be invasive. In this study, we assessed the ability of the South African strain to infect other species of Myrtaceae by testing the susceptibility of New Zealand provenance Myrtaceae. Seedlings of four native New Zealand Myrtaceae species (Metrosideros excelsa, Leptospermum scoparium, Kunzea robusta, and Kunzea linearis) were artificially inoculated in South Africa with a single-uredinium isolate of the South African strain. Fourteen days after inoculation, uredinia, and in many cases telia, had developed on the young leaves and stems of all four host species, which led to shoot tip dieback in the more severe cases. When comparisons were made between the species, K. robusta was the least susceptible to the South African strain of A. psidii, while L. scoparium and M. excelsa were the most susceptible. While only a limited number of seed families were tested, only a small proportion of the seedlings showed resistance to infection by the South African strain. This preliminary testing highlights the potential invasive risk the South African strain poses to global Myrtaceae communities, including New Zealand Myrtaceae.