An unusual Xanthophyllomyces strain from leaves of Eucalyptus globulus in Chile

Xanthophyllomyces sp. was isolated as an epiphytic red yeast from leaves of Eucalyptus glo-bulus in Concepción, Chile. Sexual reproduction was by basidiospores produced from one or rarely two metabasidia arising from a yeast cell without preceding paedogamy. The main carotenoid pigment was astaxanthin. This isolate did not cluster with the X. dendrorhous complex (including Phaffia rhodozyma) in ITS and 26S rDNA-based phylogenetic analyses. The phylloplane may be a further habitat for Xanthophyllomyces, in addition to the well-known spring sap-flows of deciduous trees and the recently-characterised ascostromata of Cyttaria hariotii.     

Structure of a defective simian virus 40 genome bearing an operator from bacteriophage lambda.

We examined further the physical structure of the simian virus 40 (SV40) and bacteriophage lambda DNA sequences in an SV40-lambda hybrid that had been propagated in monkey kidney cells. The SV40 vector portion of the hybrid, which was a small fragment isolated from a reiteration mutant of SV40, contained the site for initiation of SV40 DNA replication. Electron microscope heteroduplex and restriction endonuclease analyses revealed a tandem duplication of the SV40 vector segment linked to a 2,300-base pair portion (lambda map units 71 to 76) of the lambda immunity region. The defective hybrid genome thus harbors two origins for SV40 DNA replication in addition to the leftward operator and the N gene of lambda.     

Thyroglobulin-like immunoreactivity in the nervous system of Eisenia foetida (Annelida,Oligochaeta)

Summary Immunohistochemical studies were performed by use of specific rabbit antisera and purified antibodies to human Tg on cephalic and body sections of Eisenia foetida and on cephalic sections of Lumbricus terrestris. Secondary antisera, either fluorescein- or peroxidase-conjugated, were used to identify the immunoreaction. Immunoreactive perikarya and some immunoreactive nerve fibres were detected in both the cerebral ganglion and the ventral nerve cord of E. foetida. From 8 to 19 Tg-like positive neurons per frontal section were observed in the brain, mainly in the dorsal zone. From 2 to 4 positive perikarya per ganglion were found in sagittal sections of the ventral nerve cord with a repetitive distribution. Numerous positive neurons were also found in the cephalic segments of L. terrestris. The present results indicate that a substance immunologically related to mammalian Tg is synthesized in earthworms. This suggests that some conservative sequences of Tg structure arose very early in evolution and supports the idea of a common evolutionary origin for endocrine and nervous systems.     

Molecular approaches in pig breeding to improve meat quality.

This article reviews the advances in molecular genetics that have led to the identification of genes and markers associated with meat quality in pig. The development of a considerable number of annotated livestock genome sequences represents an incredibly rich source of information that can be used to identify candidate genes responsible for complex traits and quantitative trait loci effects. In pig, the huge amount of information emerging from the study of the genome has helped in the acquisition of new knowledge concerning biological systems and it is opening new opportunities for the genetic selection of this specie. Among the new fields of genomics recently developed, functional genomics and proteomics that allow considering many genes and proteins at the same time are very useful tools for a better understanding of the function and regulation of genes, and how these participate in complex networks controlling the phenotypic characteristics of a trait. In particular, global gene expression profiling at the mRNA and protein level can provide a better understanding of gene regulation that underlies biological functions and physiology related to the delivery of a better pig meat quality. Moreover, the possibility to realize an integrated approach of genomics and proteomics with bioinformatics tools is essential to obtain a complete exploitation of the available molecular genetics information. The development of this knowledge will benefit scientists, industry and breeders considering that the efficiency and accuracy of the traditional pig selection schemes will be improved by the implementation of molecular data into breeding programs.     

The porcine fat mass and obesity associated (FTO) gene is associated with fat deposition in Italian Duroc pigs

In humans, common variants in the fat mass and obesity associated ( FTO ) gene are associated with body mass index and obesity. Here we sequenced exon 4, parts of introns 3 and 4 and two portions of the 3'-untranslated region of the porcine FTO gene in a panel of nine pigs of different breeds and identified three SNPs. Allele frequencies of the g.276T>G ( AM931150 ) mutation were studied in seven pig breeds. This mutation was used to linkage-map FTO to SSC6. Association analyses between the g.276T>G polymorphism and several traits [pH of semimembranosus muscle and estimated breeding values (EBV) for average daily gain, back fat thickness, lean cuts, ham weight and feed:gain ratio] were carried out in 257 sib-tested Italian Large White pigs. Only feed:gain ratio showed P  <   0.05. A selective genotyping approach was applied, analysing two extreme and divergent groups of Italian Large White pigs selected on the basis of back fat thickness EBV (50 with most positive and 50 with most negative values). Fisher's exact test (two-tailed) was not significant when comparing the allele frequencies of these two groups. The same approach was used in the Italian Duroc breed for which two extreme and divergent groups of animals were selected according to visible intermuscular fat EBV. Differences of allele frequencies between these two groups were highly significant ( P  <   0.00001, P  <   0.001 and P  <   0.0001, considering all animals or only two- or three-generation unrelated animals respectively), indicating association between the analysed FTO marker and intermuscular fat deposition.     

Targeted inactivation of Mapk4 in mice reveals specific nonredundant functions of Erk3/Erk4 subfamily mitogen-activated protein kinases

Erk4 and Erk3 are atypical members of the mitogen-activated protein (MAP) kinase family. The high sequence identity of Erk4 and Erk3 proteins and the similar organization of their genes imply that the two protein kinases are paralogs. Recently, we have shown that Erk3 function is essential for neonatal survival and critical for the establishment of fetal growth potential and pulmonary function. To investigate the specific functions of Erk4, we have generated mice with a targeted disruption of the Mapk4 gene. We show that Erk4-deficient mice are viable and fertile and exhibit no gross morphological or physiological anomalies. Loss of Erk4 is not compensated by changes in Erk3 expression or activity during embryogenesis or in adult tissues. We further demonstrate that additional loss of Erk4 does not exacerbate the fetal growth restriction and pulmonary immaturity phenotypes of Erk3(-/-) mice and does not compromise the viability of Erk3(+/-) neonates. Interestingly, behavioral phenotyping revealed that Erk4-deficient mice manifest depression-like behavior in the forced-swimming test. Our analysis indicates that the MAP kinase Erk4 is dispensable for mouse embryonic development and reveals that Erk3 and Erk4 have acquired specialized functions through evolutionary diversification.