Advance in mechanism of plant leaf colour mutation

As a common mutation trait in plants, leaf colour mutation is related to the degree of chlorophyll and anthocyanin changes and the destruction of chloroplast structure. This study summarizes the latest research progress in leaf colour mutation mechanism, including the metabolic basis of plant leaf colour mutation, leaf colour mutation caused by gene mutation in the chlorophyll metabolism pathway, leaf colour mutation caused by blocked chloroplast development, leaf colour mutation controlled by key transcription factors and non-coding RNAs, leaf colour mutation caused by environmental factors, and leaf colour mutation due to the involvement of the mevalonate pathway. These results will lay a theoretical foundation for leaf colour development, leaf colour improvement, and molecular breeding for leaf colour among tree species.

Effect of cage enrichment on the welfare of farmed foxes

The aim of the study was to use behavioural and cortisol tests to determine whether cage enrichment (observation shelves, wooden sticks for gnawing) improves the welfare of farmed foxes (Vulpes vulpes). The paper discusses welfare criteria such as "expression of other behaviours", "good human–animal relationships" and "positive emotional state". The study covered 60 young foxes. After weaning, the animals were placed in standard cages, two individuals per cage. The foxes were divided into three groups. In the control group, no additional cage enrichment was provided. Group I was provided with observation shelves; group II was provided with wooden gnawing sticks. During the experiment the foxes underwent repeated tests: empathic test, feeding test and salivary cortisol test. The data obtained were analysed statistically (ANOVA, Tukey’s test, correlation), taking into account the following variables: the impact of cage enrichment, animal gender, temperament, and colour mutation. The study did not show conclusively that the use of cage enrichment affects animal temperament or the level of cortisol. However, in the group with gnawing sticks, the level of cortisol in the second measurement was significantly lower in comparison with other groups. This indicates that satisfying the need to gnaw objects reduces stress in foxes. The study showed a high correlation between the empathic and the feeding test, both of which are useful for testing the emotional state of foxes and the human–animal relationship.

Investigation of the premelanosome protein (<i>PMEL</i> or <i>SILV</i>) gene and identification of polymorphism excluding it as the determinant of the dilute locus in domestic rabbits (<i>Oryctolagus cuniculus</i>)

After the rediscovery of the Mendel’s laws, the domesticated European rabbit (Orycolagus cuniculus) has been the objective of pioneering studies on coat colour genetics. However, despite the early role of this species in defining genetic mechanisms determining this phenotypic trait, only recently a few loci have been characterized at the molecular level analysing also in rabbits genes already shown to affect coat colour in mice. We herein investigated the rabbit premelanosome protein (PMEL) gene, also known as melanocyte protein Pmel 17 (PMEL17) or silver (SILV), as mutations in the homologous gene in mice and other species produce phenotypic effects similar to what is observed in the dilute coat colour in rabbit. The rabbit dilute locus is determined by a recessive coat colour mutation that dilutes the black to blue (grey) interacting with the basic colours influenced by the agouti and extension loci. To investigate this candidate gene, we isolated and sequenced cDNAs as well as portions of intronic and exonic regions of the PMEL gene in several rabbits with different coat colours and identified single nucleotide polymorphisms, including several missense mutations. One polymorphism, positioned in intron 7, was genotyped in a family in which there was segregation of the dilute coat colour. The results excluded PMEL as the causative gene for the dilute locus in rabbits, shortening the list of candidate genes that should be analysed to identify the mutation determining this phenotypic trait.