Ovine rumen papillae biopsy via oral endoscopy; a rapid and repeatable method for serial sampling

AIMS: To explore and validate the utility of rumen endoscopy for collection of rumen papillae for gene expression measurement.

METHODS: Four adult Coopworth ewes were fasted for either 4 or 24 hours. Animals were sedated, placed in a dorsally recumbent position at 45 degrees with the head upright, and an endoscope inserted via a tube inserted into the mouth. Biopsies of rumen papillae were taken from the ventral surface of the rumen atrium under visual guidance. Two biopsies were collected from one of the animals that had been fasted for 4 hours, and three from one of the animals that had been fasted for 24 hours. Video of the rumen atrium and reticulum was also collected. The animals recovered uneventfully. Biopsies were subsequently used for extraction and sequencing of mRNA.

RESULTS: The ventral surface of the rumen atrium was accessible after 4 hours off pasture, but a larger region was accessible after 24 hours of fasting. Sedation allowed access for endoscope use for around 5 to 10 minutes after which increased saliva flow was noted. Rumen papillae biopsies were easily collected, with samples from a variety of sites collected in the ～10 minute time window. High quality RNA was obtained for stranded mRNA sequencing. Of the resulting reads, 69–70% mapped uniquely to version 3.1 of the ovine genome, and 48–49% to a known gene. The rumen mRNA profiles were consistent with a previously reported study.

CONCLUSIONS: This method for obtaining rumenal tissue was found to be rapid and resulted in no apparent short or long term effects on the animal. High quality RNA was successfully extracted and amplified from the rumen papillae biopsies, indicating that this technique could be used for future gene expression studies. The use of rumen endoscopy could be extended to collection of a variety of rumen and reticulum anatomical measurements and deposition and retrieval of small sensors from the rumen. Rumen endoscopy offers an attractive and cost effective approach to repeated rumen biopsies compared with serial slaughter or use of cannulated animals.     

The percolation phase transition in sea Ice

Sea ice exhibits a marked transition in its fluid transport properties at a critical brine volume fraction pc of about 5 percent, or temperature Tc of about -5 degreesC for salinity of 5 parts per thousand. For temperatures warmer than Tc, brine carrying heat and nutrients can move through the ice, whereas for colder temperatures the ice is impermeable. This transition plays a key role in the geophysics, biology, and remote sensing of sea ice. Percolation theory can be used to understand this critical behavior of transport in sea ice. The similarity of sea ice microstructure to compressed powders is used to theoretically predict pc of about 5 percent.     

Echinoderm calcite: single crystal or polycrystalline aggregate

Electron microscopy of natural and broken surfaces of echinoid skeletal plates reveals that the interior portions have the morphology of a single crystal, whereas the exterior is a polycrystalline aggregate with preferred orientation. These data help to resolve earlier contradictory x-ray and optical evidence.     

Quality Parameters for Alpaca (Vicugna pacos) Semen are Affected by Semen Collection Procedure

Artificial insemination (AI) is poorly developed in camelids owing to the difficulty in collecting high quality semen and the highly viscous nature of the semen. Semen collected by artificial vagina (AV) is often of low quality and must be improved before any further development of AI technology can occur. The present study investigated the effects of adding a cervix‐like stricture to the AV, presence of females, collecting semen into Androhep^®, skim‐milk or Tris diluents, and catalase supplementation (0, 100, 200 or 600 units/ml) of Tris diluent on alpaca semen quality parameters. The addition of a cervix‐like stricture increased mating length (p < 0.05), whilst the presence of females during semen collection did not improve semen quality parameters (p > 0.05). Collection of semen into Tris diluent improved sperm motility (58.0 ± 11.9%) compared with the control (34.0 ± 10.8%; p < 0.05), Androhep^® (33.5 ± 10.7%) and skim‐milk diluents (28.2 ± 10.4%). Semen viscosity was reduced by collection into Androhep^® (4.6 ± 1.7 mm) and skim‐milk diluents (3.6 ± 1.3 mm) compared with Tris diluent (5.7 ± 2.1 mm) and no collection medium (9.3 ± 3.5 mm; p < 0.05). Tris diluent supplemented with 100, 200 or 600 units/ml catalase increased semen viscosity (5.0 ± 3.2 and 4.9 ± 3.2 mm). Collection of alpaca semen by AV into Tris diluent increased semen quality facilitating further development of AI technology in alpacas.     

Lepidocrocite iron mineralization in keratose sponge granules

Reddish-brown granules embedded in the spongin fibers of some keratose sponges consist of very fine crystallites of poorly organized lepidocrocite, gamma FeOOH. This is the first occurrence of crystalline iron mineralization in the phylum Porifera and the first indication of hard tissue formation among the Keratosa.     

The Effects of Blastomere Biopsy and Oxygen Tension on Bovine Embryo Development, Rate of Apoptosis and Interferon-τ Secretion

A series of experiments was performed to examine the effects of blastomere biopsies on subsequent development of IVF-derived bovine embryos. The first experiment was designed to assess the optimal time for blastomere removal. One blastomere was removed either 48 or 72 h after IVF. Biopsy at 48 h resulted in 17.2% of embryos proceeding to the blastocyst stage, which was lower than when biopsies were performed at 72 h (37.5%, p < 0.05). In the second experiment, embryos were cultured either under atmospheric or 5% O(2) following blastomere removal. Biopsies had no effect on rate of blastocyst formation with 36% of controls and 33.7% of biopsied embryos proceeding to that stage. However, culture under 5% O(2) significantly increased the number of blastocysts from 29.9% to 40.3% (p < 0.05). This effect was significant in both biopsied and control embryos. In the final experiment, biopsied embryos were again cultured under different oxygen tension. Blastocysts were collected and cultured individually for 48 h in medium droplets in their respective O(2) concentration after which time the medium was assayed for concentration of interferon-tau (IFN-tau). Reduced O(2) concentration again significantly increased blastocyst formation from 24.9% to 41.9% (p < 0.05). IFN-tau secretion was not affected by biopsies, but culture under atmospheric O(2) resulted in significantly increased IFN-tau concentration in medium droplets (12274.0 +/- 2825.9 pM vs 5046.5 +/- 2562.2 pM; p < 0.05).