Estimation of genetic parameters for milk traits in Romanian local sheep breed

ABSTRACT Objective. Estimate the genetic parameters for milk traits in a Romanian local sheep population Teleorman Black Head. Material and methods. Records of 262 sheep belonging to 17 rams and 139 ewes were used in the study. The following traits were investigated: milk yield, fat yield, protein yield, fat percentage and protein percentage. The genetic parameters were estimated using the Restricted Maximum Likelihood method, with a model including maternal effects. Results. The results from our study revealed that direct heritability estimates were moderate for milk yield (0.449), fat yield (0.442), protein yield (0.386) while for protein percentage (0.708) and fat percentage (0.924) were high. The high direct and maternal genetic correlation was between milk yield and protein yield (0.979, 0.973) and between protein yield and fat yield (0.952, 0.913) while the phenotypic correlation between the milk yield and fat yield (0.968), the milk yield and protein yield (0.967), fat yield and protein yield (0.936) was high and positive. Conclusions. The genetic parameters are important in selection program on this breed for genetic improvement

Relationship between gene polymorphism and milk production traits in Teleorman Black Head sheep breed

ABSTRACT Objective. This study is a preliminary step of a larger national program aimed to develop a strategy for “in situ” preservation of Teleorman Black Head sheep population. In this paper we estimated the effect of β-lactoglobulin, casein and prolactin on some quantitative and qualitative milk traits in this local sheep population. Material and methods. Genotyping methodology included PCR for CSN3 (A and B alleles) and PCR-RFLP for LGB (A and B alleles) and PRL (T and C alleles), respectively. Repeated milking and milk composition analysis were used for the polymorphism effect estimation. Results. No association between CSN3 polymorphism and milk traits was found. Effect of LGB on production traits was quite constant. Genotype AA performed better than BB. PRL marker effect showed small differences than LGB. Concerning milk, fat and protein yield, AA genotype for PRL had a smaller positive impact than AA genotype for LGB. Regarding fat and protein content, PRL showed a negative effect for AA and positive for BB genotype, respectively. Conclusions. Positive association between LGB and milk yield and composition recommend this candidate gene like marker for a future MAS program. Although PRL gene is also associated with an increased milk quantity, inverse response over milk composition must be considered in MAS strategy. Our study demonstrated that both LGB and PRL markers could became an advent of MAS utilization in Romanian dairy sheep breeding industry.   RESUMEN Objetivo. Este estudio es un paso preliminar de un programa nacional más amplio destinado a desarrollar una estrategia para la conservación “in situ”de la población de ovejas Cabeza Negra de Teleorman. En este trabajo se estimó el efecto de la β-lactoglobulina, caseína y prolactina en algunos rasgos cuantitativos y cualitativos de la leche en esta población de ovejas locales. Material y métodos. Metodología de PCR para genotipificación incluido CSN3 (A y B alelos) y PCR-RFLP para LGB (A y B alelos) y PRL (T y C alelos). Análisis y composición de la leche de ordeños repetidos se utilizaron para estimación el efecto del polimorfismo. Resultados. No se encontró asociación entre el polimorfismo y la leche rasgos CSN3. Efecto de LGB en los rasgos de producción era bastante constante. Genotipo AA obtenido mejores resultados que BB. Efecto marcador PRL mostró pequeñas diferencias que LGB. En cuanto a la leche grasa y proteína el genotipo AA para PRL tuvo un impacto positivo más pequeño que el genotipo AA para LGB. En cuanto a contenido de grasa y proteína, PRL mostró un efecto negativo para AA y positivo para BB genotipo. Conclusiones.La asociación positiva entre LGB y la producción de leche y la composición recomienda este gen candidato como marcador para un futuro programa de MAS. Aunque gen PRL también se asocia con un incrementoen la cantidad de leche, la respuesta inversa sobre composición de la leche debe ser considerado en la estrategia de MAS. Nuestro estudio demostró que los marcadores tanto LGB y PRL podrían venir a ser utilizados en MAS en la industria rumanade cría deovejas lecheras

Matrix Metalloproteinases in Cytotoxic Lymphocytes Impact on Tumour Infiltration and Immunomodulation

To efficiently combat solid tumours, endogenously or adoptively transferred cytotoxic T cells and natural killer (NK) cells, need to leave the vasculature, traverse the interstitium and ultimately infiltrate the tumour mass. During this locomotion and migration in the three dimensional environment many obstacles need to be overcome, one of which is the possible impediment of the extracellular matrix. The first and obvious one is the sub-endothelial basement membrane but the infiltrating cells will also meet other, both loose and tight, matrix structures that need to be overridden. Matrix metalloproteinases (MMPs) are believed to be one of the most important endoprotease families, with more than 25 members, which together have function on all known matrix components. This review summarizes what is known on synthesis, expression patterns and regulation of MMPs in cytotoxic lymphocytes and their possible role in the process of tumour infiltration. We also discuss different functions of MMPs as well as the possible use of other lymphocyte proteases for matrix degradation

Metal Organic Vapour Phase Epitaxy for the Growth of Semiconductor Structures and Strained Layers

The technological development of semiconductor materials started in the period following the second world war. In the electronics industry, the first transistors were fabricated from germanium, later from silicon. It was soon realized that also the AIII–BV or AII – BVI materials (most often simply termed III–V or II–VI materials) exhibited semiconductive behaviour. The energy difference between the valence band and the conduction band made them candidates for electronic devices which can absorb or emit phonons over a range of frequencies (wavelengths). Direct bandgap materials such as gallium arsenide (GaAs) were suitable for devices in which efficient electron-hole recombinations could take place and high efficiency light emitting devices were a possibility. Stimulated emission was first demonstrated in 1970 with the preparation of the single heterojunction and the double heterojunction laser diodes. These devices are multiple layer structures with a thin waveguide region contained between layers of larger bandgap and different refractive index (for confinement of carriers and radiation, respectively, in the active region). A basic laser diode chip consists of two parallel facets, (110) planes, which are prepared by cleavage and act as mirrors. The Fabry-Perot cavity is defined by these two parallel facets and the passive (cladding) layers. In the longitudinal direction current definition is by mesa etching and/or stripe-contact metallization