Calves Born after Direct Transfer of Vitrified Bovine In Vitro-produced Blastocysts Derived from Vitrified Immature Oocytes

Vitrification has been the method of choice for the cryopreservation of bovine oocytes, as rapid cooling decreases chilling sensitivity. The aim of this study was to determine the in vitro and in vivo survival and the viability of immature oocytes vitrified using super‐cooled liquid nitrogen. Immature oocytes were randomly allocated to three groups: (i) non‐vitrified control group, (ii) vitrified in normal (?196°C) liquid nitrogen (LN₂) and (iii) vitrified in super‐cooled LN₂ (≤?200°C). Open‐pulled glass micropipettes were used as vitrification containers. Immature oocytes were in vitro‐matured, fertilized and cultured to the blastocyst stage. In vitro viability was assessed by cleavage and blastocyst rates on days 2 and 7 of culture respectively. Vitrified blastocysts derived from the immature vitrified oocytes were directly transferred to synchronous recipients. The in vitro embryo development of vitrified immature oocytes was not influenced by the LN₂ state. After direct transfer (one embryo per recipient) of 16 embryos obtained from immature vitrified oocytes (eight from each vitrified group), two healthy calves were born in each group. These results indicated that vitrification of immature bovine oocytes using glass micropipettes under normal or super‐cooled LN₂, resulted in viable blastocysts and live calves following in vitro embryo production.     

Pathological findings in the bulbourethral glands of bulls

The bulbourethral glands of 323 Bos indicus or B. indicus crossbred bulls more than 1 1/2 years old were examined in an abattoir study. Bulbourethral adenitis was diagnosed grossly and confirmed by histological examination in 4 (1.2%). Unilateral chronic interstitial inflammation was seen in 2 cases; one of these was associated with a degenerative-type seminal vesiculitis. In the others adenitis was bilateral; in one case it was associated with a concretion and foreign (plant) material in the principal duct of the left bulbourethral gland; in the other bilateral case, numerous calculi were present and microscopically, a chronic active and diffuse inflammation was observed. Chemical analysis of the calculi showed calcium oxalate and tricalcium phosphate to be the most important components. Corynebacterium spp was isolated from the lesion with multiple calculi but attempts to isolate Chlamydia spp, Mycoplasma spp and Brucella abortus from the 4 adenitis cases were unsuccessful. Congenital abnormalities such as glandular fusion (2.2%) or unilateral aplasia (0.6%) were also observed. Cysts were the most common finding (19.2%), and duct dilation was frequent (7.1%). The significance of these findings in relation to fertility is considered.     

Complete genome sequences and properties of Spartina mottle virus isolates from hybrid Bermuda grass (Cynodon dactylon × Cynodon transvaalensis)

Full genome sequences are presented for two isolates of Spartina mottle virus (SpMoV) from two accessions of the hybrid turf grass Cynodon dactylon × C. transvaalensis (Bermuda grass, green couch), originally from the USA but detected during post-entry quarantine in Australia. Both isolates had a genome of 9,346 nucleotides, encoding a single polyprotein of 3,029 amino acids and predicted to be cleaved into 10 mature proteins. Phylogenetic analysis strongly supported placement in a new genus within the family Potyviridae. The isolates possess 715–780 × 11–12 nm flexuous virions and produce cylindrical (pinwheel) inclusions in infected cells. They were mechanically transmitted to several species in the Poaceae including Zea mays (maize, sweet corn), Chloris gayana (Rhodes grass), and Echinochloa colona (awnless barnyard grass).     

Feline leukemia virus: occurrence of viral antigen in the tissues of cats with lymphosarcoma and other diseases

Felinie leutkemia viruts antigen is demonstrable by immunodiffusion with rabbit precipitating antiserum to purified felinie leukemia virus. The felinie leukemia virus antigen was found in the tissues of 25 of 33 cats with lymphosarcoma and of 5 of 13 cats with infectious peritonitis. Its presence was correlated with the occurrence of felinie leukemia virus demonstrable by electron microscopy. The one clinically normal cat giving a positive test for feline leukemia virus antigen belonged to a household in which two cats had developed lymphosarcoma. With the exception of a dog with lymphosarcoma induced by feline leukemia virus, the antigent was absent from lymphosarcoma and nonlymphomatous tumors of other species (man, dog, cow, goat, or pig).