Summary: Heimann et al. (2009)

Veterinary practice, research and drug development has relied heavily on blood examination in laboratory animals. One of the common methods used for extracting blood from rodents is the retrobulbar venous plexus puncture. The advantage to this technique is the ability to harvest high volumes of blood, however, this technique can lead to extensive tissue damage, so much so that this method is only currently accepted if the procedure results in termination. Heimann et al. (2009) developed a novel puncture technique for rodents from the sublingual vein as an alternative to the retrobulbar venous plexus puncture technique. They found that large volumes of blood could be obtained using this method and that the method was suitable for rats, mice and hamsters. However, the sublingual vein in guinea pigs is not peripherally located, making this method impossible for these rodents. Heimann et al. (2009) also noted that sublingual venepuncture resulted in less tissue destruction in mice and, therefore, recommended this method over the retrobulbar venous plexus puncture technique.

Summary: Jozet-Alves et al. (2012)

Cerebral lateralization, defined as localization of function on either the right or left sides of the brain, was thought to be an exclusively human trait until recently. Lateralization is often perceived as asymmetries in motor behaviour, for example, a preference for using a particular hand, or turning in a particular direction. While lateralization studies in vertebrates are now common place, lateralization studies in invertebrates are more rare, although observations appear to parallel that seen in vertebrates. While lateralization in vertebrates can vary within an individual across its development, this was unknown in invertebrates. Jozet-Alves et al. (2012) examined lateralization during postembryonic development in juvenile cuttlefish Sepia officinalis, specifically focusing on when juveniles begin to show side-turning preferences. They found that juvenile cuttlefish progressively developed a left-turning bias between the ages of 3 and 45 days posthatch, but this was dependent on the presence of shelters. Jozet-Alves et al. (2012) suggest that this preference for turning left is a result of eye-use preference. This establishment of visual lateralization can provide juveniles with greater behavioural efficiency at dispersal, but increasing their ability to detect escape routes during hunting. It is possible that, by determining the role that the right visual field plays during prey-seeking in cuttlefish, this may provide evidence for homology for lateralization between vertebrates and invertebrates.

Summary: Hasegawa et al. (2013)

The sensory trap hypothesis proposes that courtship behaviour of males that mimic food-begging behaviour of offspring is a consequence of signal evolution. This results from males attempting to match stimuli that stimulate the female response in other contexts (for example, in parental care). As a result, females respond and male mating success increases. To humans, male courtship behaviour in many birds appears similar to food-begging behaviour of chicks. It is unclear, however, whether this behaviour does actually elicit a parental care response by females during courtship, indicative of a sensory trap. Hasegawa et al. (2013) studied barn swallows Hirundo rustica gutturalis and found that males make enticement calls that are structurally similar to nestling begging calls. When they played back these vocalizations to females during courtship, they observed females responding, even when nestlings were not present. Hasegawa et al. (2013) suggest that this represents a sensory trap, whereby a males mimic a signal which evokes a female response for an alternate behaviour (in this case, parental care).

Summary: Kuroki et al. (2013)

The interaction between transcription factor function and epigenetic status, which includes histone modification, defines developmental gene expression. Mammalian sex determination is influenced by various transcription factors, but the epigenetic regulation of this process is still unclear. Kuroki et al. (2013) studied sex reversal (male to female) in mice that lacked a particular enzyme - H3K9 demethylase Jmjd1a. They found that this enzyme regulates the expression of Sry gene, which is the mammalian Y chromosome sex-determining gene. Kuroki et al. (2013) showed that Jmdj1a directly controls Sry expression in a positive manner through its regulation of H3K9me2 marks. Their study demonstrates the important role that histone demethylation plays in mammalian sex determination.