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Ruminosignatures associated with methane emissions and feed efficiency across geographies and cattle breeds.

The cattle rumen microbiota represents a complex and dynamic ecosystem whose organization and relationship to host phenotypes are important for food security and environmental sustainability. We analyzed rumen microbiota profiles from 2496 cattle representing five breeds and production systems across five countries, identifying microbial co-abundance groups termed Ruminosignatures. We detected 14 distinct Ruminosignatures, including 2 observed across all populations dominated by Prevotella and UBA2810. Additional Ruminosignatures showed breed- and diet-specific patterns and collectively explained 96%-99% of variance in rumen microbial composition. Integrative cross-country analysis confirmed 10 out of 14 Ruminosignatures identified in cohort-specific analyses. Several Ruminosignatures were associated with methane emissions and feed efficiency traits and were partially under host genetic control, with heritability estimates ranging from 0.09 to 0.58. Structural equation modeling revealed consistent negative genetic and phenotypic correlations between the UBA2810-dominated Ruminosignature (RS_UBA2) and methane emissions across cohorts (rg = -0.40 to -0.65), with structural coefficients concordant in sign across all populations, supporting the expected direction of phenotypic response to selection on RS_UBA2. Meta-analysis confirmed positive associations of RS_UBA2 with average daily gain and negative associations with methane-related traits and feed conversion ratio. Functional genome-based predictions suggested RS_UBA2 may reduce methanogenesis through alternative hydrogen utilization pathways competing with methanogenic archaea. Production system type influenced both Ruminosignature occurrence and relationships with host phenotypes, emphasizing the relevance of context-specific strategies for microbiome modulation. Our findings highlight the potential of the Ruminosignatures framework for microbiome-informed breeding programs aimed at improving feed efficiency while reducing the environmental impact of cattle production.

Animals↗

Chromosomal fragile site expression in dogs: I. Breed specific differences.

Peripheral blood lymphocytes from clinically normal Doberman pinscher and boxer dogs were cultured for folate-sensitive and, in preliminary studies, aphidicolin-inducible fragile site expression. Both autosomal and X chromosomal fragile sites were observed in canine cells cultured under folate/thymidine depletion and in cells cultured in medium containing aphidicolin. Results from the three dogs evaluated for both folate-sensitive and aphidicolin-inducible fragile site expression showed that the frequency of fragile site expression was significantly (P less than 0.05) greater in cells cultured in medium containing aphidicolin than in cells cultured in folate/thymidine-depleted medium. Cells from the boxer dog expressed a high percentage (66.67%) of aphidicolin-inducible fragile sites in contrast to the Doberman pinscher dog in which only 21.10% of the lymphocytes expressed aphidicolin-inducible fragile sites. The frequencies of spontaneous and folate-sensitive fragile site expression did not vary significantly by breed of dog. Age of dog was significantly and positively correlated with frequency of folate-sensitive fragile site expression in dogs of the boxer breed, but not in dogs of the Doberman pinscher breed. The dog X chromosome expressed three folate-sensitive and aphidicolin-inducible fragile sites. The G-band location of these three fragile sites showed homology with three recognized constitutive common fragile sites on the human X chromosome: Xp22, Xq21, and Xq27.2. Two specific autosomal fragile sites were identified, one on the distal end of the long arm of chromosome 1 and one on the distal end of the long arm of chromosome 8. Other autosomal fragile sites were also apparent but could not be assigned reliably to specific chromosomes.

Aging↗

Breeding and biotechnology for improving berry nutritional quality.

Breeding and biotechnological approaches are currently used to increase the content of specific bioactive components of plants, but the manipulation of plant metabolism is still not easy to address. There is an increasing awareness that multiple genetic and environmental factors affect production and accumulation of bioactive compounds, but these factors are rarely taken into account when fruit is marketed. Rigorous and unprejudiced evaluation of scientific evidence requires a defined set of criteria and methods of evaluation, particularly when breeding and biotech programs are aimed of producing new varieties with improved nutritional values combined with high plant production efficiency and fruit quality. In order to develop new genotypes and commercial cultivars the availability of new sources of Quality Attributes (QA) and Nutritional Attributes (NA) should be explored. In the strawberry, wild species such as F. virginiana glauca and F. vesca are good sources of bioactive compounds, but in raspberries the introduction of the wild germplasm (R. parvifolium) did not improve the nutritional quality of fruit. The methods available for detecting fruit TAC, combined with TPH and other quality parameters such as sugars, total acidity and fruit color, can be proposed as excellent tools for developing a fast and reliable program for screening large breeding populations for high nutritional quality genotypes. Furthermore, NA can represent a useful tool to facilitate analysis of "substantial equivalence" of transgenic and control derived fruit.

Antioxidants↗

Long- and short-haired Weimaraner dogs represent two populations of one breed.

Weimaraners represent an old breed of hunting dogs. Today, two coat types are commonly distinguished, the more common short-hair (SH) and the long-hair (LH) variety, the latter having arisen from the SH Weimaraners. In order to analyze genetic variation in the coat varieties, we genotyped nine single nucleotide polymorphisms (SNPs) of the ABCA4 gene locus as well as six highly variable microsatellites scattered over the canine genome in the SH and LH populations. Three out of nine SNPs showed two alleles, allelic frequencies at two of these polymorphic sites differed significantly between SH and LH Weimaraners. Haplotype diversities for the three informative SNPs revealed higher estimates for the SH (0.515) than for the LH variety (0.364). In addition, two of six microsatellite markers showed significant differences in allelic frequencies between SH and LH Weimaraners. Unexpectedly, genetic diversities for all but one microsatellite were greater in LH than in SH Weimaraners. Similarly, the mean intra-individual genetic distance based on microsatellite markers was more pronounced in the LH population (0.62 for SH vs. 0.65 for LH) suggesting again closer genetic relationships among SH than LH Weimaraners. Taken together, the results of SNP analysis can be interpreted as reflections of early breed development whereas microsatellites mirror rather recent breeding strategies in the Weimaraner populations.

Animals↗

Photomanipulation of sexual maturation and breeding cycle of the steppe polecat (Mustela eversmanni) and other techniques for more rapid propagation of the species.

Twenty steppe polecats were divided into 2 groups, each consisting of 4 males and 6 females, and subjected to either a natural photoperiod (controls) or alternating periods of short (8 h light/16 hr dark for 8-9 weeks) and long days (16 h light/8 h dark for 16-20 weeks). The experimental photoperiod significantly accelerated sexual maturation in both sexes, with males developing maximal testis size within 57 days and females breeding after an average of 52 days exposure to 16L/8D. Males in the experimental group completed 2 1/2 testicular cycles and participated in mating during 3 successive breeding seasons during the 18 month period whereas males in the control group completed a single testicular cycle and only had an opportunity to mate during a single breeding season. Females in the experimental group produced 3 litters whereas females in the control group only gave birth to a single litter. Litter size averaged 6.9 +/- 2.0 (n = 23) and did not significantly differ with age, parity, or treatment. Pseudopregnant females returned to estrus within 12 days after the expected date of parturition, were bred, and gave birth to kits. Polecats which were subjected to the experimental photoperiods completed more molting cycles and underwent more photoperiod-induced changes in body weight than those in the control group. Death or removal of kits within 8 days after birth resulted in 12/12 females returning to estrus within 6-26 days. Eleven of these females were remated and gave birth to kits. Eight domestic ferrets readily accepted neonatal polecat kits and 5 successfully reared kits, although kit survival was quite poor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

The comparative haematology of cross-bred and indigenous east African goats of Tanzania and breeds reared in Denmark.

Erythrocyte counts, haematocrit, haemoglobin concentration, red blood cell indices, total and differential leukocyte counts were determined in 202 cross-bred and 14 indigenous East African goats aged 6-12 months and also in 59 Norwegian dairy goats, of which 24 were 15-45 days old, 8 were 8 months old and 27 were over 3 years and pregnant. These were reared in Tanzania. Comparisons were made with 24 Dwarf and 57 Danish Landrace goats at 6-12 months of age and 76 adult pregnant Danish Landrace goats reared in Denmark. The purpose was to determine reference ranges for cross-bred and indigenous East African goats and to compare these with those of other breeds. The haemoglobin concentration, haematocrit, erythrocyte and white blood cells were lowest in the Norwegian kids. The highest values were observed in 6-12-month-old goats in all the breeds, whereafter they decreased to relatively constant adult levels. The mean corpuscular volumes were highest in kids followed by adult pregnant Norwegian and Danish Landrace goats, and lowest in 6-12 months old goats. East African and cross-bred goats had the smallest mean corpuscular volumes. The haemoglobin concentration, erythrocyte and leukocyte counts were highest in indigenous East African, followed by young Norwegian and cross-bred goats. The mean corpuscular haemoglobin concentration was highest in the cross-breds, while the mean corpuscular haemoglobin was higher in pregnant than in other goats. The age and breed differences were statistically significant.

Animals↗

Permeability of the endothelium and partitioning of the pulmonary blood flow resistance in isolated perfused pig lungs: effects of breed and age.

The right and left lungs of 5 healthy Minipigs and of 13 healthy Landrace piglets were isolated, perfused at constant pressure and maintained in an isogravimetric state under zone III conditions (pulmonary venous pressure greater than alveolar pressure). By applying the double, arterial and venous, occlusion technique, the total blood flow resistance (R) was partitioned into four components: arterial (Ra), pre- (Ra') and post-capillary (Rv') and venous (Rv). The capillary filtration coefficient (Kf,c) was evaluated by measuring the weight gained by the lungs when the arterial and venous pressures were suddenly increased. In the youngest Landrace piglets (5 weeks old), there was an uncontrolled vasoconstriction which sometimes prevented perfusion of the lungs and induced a large increase in Rt. These high values of Rt were decreased by tolazoline administration. The values of Rt recorded in older pigs (12-13 weeks old) were lower in Minipigs (33.66 +/- 3.77 cmH2O min L-1 per 100 g of lungs; n = 5) than in Landrace piglets (55.20 +/- 6.18 cmH2O min L-1 per 100 g; n = 5). This breed difference was due to the differences in Ra' and Rv'. The mean values of Kf,c were 0.193 +/- 0.015 and 0.202 +/- 0.029 ml min (cmH2O)-1 per 100 g of the lungs in Minipigs and Landrace piglets respectively. All these parameters were stable for the 3 hours following the equilibrium period. It was concluded that: (1) There is an age-related maturation of the control of the vasomotor tone in porcine lungs. (2) Pulmonary microvascular haemodynamics are influenced by the breed of the pigs. (3) There was no difference in the Kf,c values between both the breeds. (4) A comparison of the values reported for dogs and rabbits with our data shows that the pre- and post-capillary resistances and, to a lesser extent, the arterial and venous resistances are relatively high in pigs.

Age Factors↗

Pig production in the Solomon Islands. III. The influence of breed, diet and housing on reproduction and growth.

In the Solomon Islands pigs grow slowly and sows have small litters. An experiment using 124 pigs in 16 litters from eight sows compared the effect of village breed, village diet and village husbandry which encouraged infection of pigs with Stephanurus dentatus, with the effect of European breed, commercial rations and a system of management which ensured freedom from S. dentatus infection on the productivity of pigs. It was shown that the village diet was markedly inferior to the commercial rations and had by far the greatest influence of any of the three factors studied on the parameters measured. The village breed was not inferior in litter size or growth rate when fed on the village diet, but was inferior in growth on the commercial diet. No harmful effects of the village husbandry system were detected on either type of pig but this may have been due to the lightness of S. dentatus infections.

Animal Feed↗

Reproductive performance of three fat-tailed breeds of sheep mated to native, Corriedale and Targhee rams.

Reproduction and lamb production of three fat-tailed, carpet-wool Iranian breeds of sheep; Karakul (130 ewes), Mehraban (103) and Baluchi (119) were studied. The ewes were mated either as purebreds or with Corriedale or Targhee rams. The overall least-squares means for ewes mated (showed oestrus) or ewes exposed, ewes lambed or ewes mated, lambs born of ewes lambing (prolificacy), lambs born alive of total lambs born, lambs weaned of live lambs born, lambs weaned (75 days of age) of ewes mated, kg lamb weaned per ewe mated and kg lamb weaned per 100 kg ewe mated were 98.3%, 93.5%, 103.1%, 94.9%, 97.8%, 90.0%, 18.2 kg and 38.4 kg respectively. The native breeds were not different for any of the traits studied except for prolificacy which was higher in Mehraban than in Karakul. Purebred matings did not differ from the crossbred matings for any of the traits concerning the number of lambs but crossbreeding improved kg lamb weaned per ewe mated (9.2%, P = 0.08) and kg lamb weaned per 100 kg ewe mated (10.0%, P less than 0.05). Among the three native breeds Karakul showed the largest improvement when crossed with the exotic rams for the traits concerning kg lambs weaned. Corriedale and Targhee rams had similar effects on all the traits studied. A lower percentage of virgin ewes showed oestrus, had a lower twinning rate and productivity compared with the mature ones. Sex was not a significant source of variation in lamb livability.

Age Factors↗

Breed and environmental influences on weaner lamb production in Zimbabwe.

Performance of the Dorper and Mutton Merino breeds and their crosses was assessed from 1,305 ewe and 1,453 lamb records from six lambing seasons. Dorper and Mutton Merino were mated in all combinations under an accelerated lambing system and crossbred females were mated to Suffolk rams. The Dorper and Mutton Merino breeds were not significantly different for fertility, pre-weaning lamb growth and survival. Suffolk sired lambs from crossbred ewes grew rapidly and were heaviest at birth and at weaning. They also survived better than lambs from the other breeding groups and this contributed to the higher weaning rate (P less than 0.05) in crossbred ewes. Weight of weaned lambs per ewe exposed to the ram per season was 12% higher (P less than 0.05) in the Dorper than the Mutton Merino ewes. However lifetime production was 28% higher (P less than 0.01) in Mutton Merino ewes due to significantly superior longevity. Crossbred ewes were highly productive. Individual heterosis was not significant but estimates were positive for most traits. Growth rate and survival of lambs increased as age of dam increased to 48 and 40 months respectively. Lambs born to previously non-lactating ewes were heavier and survived better than lambs born to ewes lactating in the previous season. Lambs born and reared as singles were 25% heavier at birth (P less than 0.001) and 52% heavier at weaning (P less than 0.001) than those born and reared as twins. Male lambs grew faster and were 7% heavier at weaning than females (P less than 0.001).

Animals↗

Susceptibility of three breeds of Ugandan goats to experimental infection with Trypanosoma congolense.

This study has indicated that differences in susceptibility to Trypanosoma congolense infection exist among the 3 main breeds of goats in Uganda namely, Kigezi, Mubende and Small East African (SEA). The Kigezi goats appeared to be the most susceptible suffering more severe anaemia, greater retardation of growth and more deaths than the other 2 breeds following experimental infection with Try-panosoma congolense. The Small East African goats appeared to be least susceptible. Following treatment after 84 days of infection, the SEA goats responded much better than the other 2 breeds. By 4 weeks after treatment with diminazene aceturate, the packed red cell volumes of the treated SEA goats were similar to those of control SEA goats while those of the Mubende and Kigezi goats were still much lower than those of control animals.

Anemia↗

Interactions of the mGluR5 gene with breeding and maternal factors on startle and prepulse inhibition in mice.

Sensorimotor gating, measured by prepulse inhibition (PPI), is a fundamental form of information processing that is deficient in schizophrenia patients and mice lacking the gene for metabotropic glutamate receptor 5 (mGluR5). Both breeding strategies and mothering behaviors are capable of influencing the behavioral phenotype of knockout (KO) mice. Previous studies found a PPI deficit and increased startle magnitudes in mGluR5 KO mice derived from homozygous matings. Here we compared the PPI of mGluR5 wildtype (WT) and KO mice derived from heterozygous matings to that seen in mice derived from homozygous matings. Possible influences of postnatal mothering behaviors were examined using two different methods of cross-fostering. The potential developmental nature of the PPI deficit of the mGluR5 KO mice was also addressed via acute administration of the mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) to C57BL/6J mice. The mGluR5 KO mice exhibited reduced PPI independently of breeding strategy or postnatal mothering behavior. Startle magnitude, however, varied with breeding strategy. The PPI deficit seen in the mGluR5 KO mice is not mimicked by acute administration of an mGluR5 antagonist, and is therefore most likely due to compensatory alterations in neuronal circuitry occurring during development independent of maternal behaviors in the postnatal environment.

Animals↗

Molecular diversity in French bread wheat accessions related to temporal trends and breeding programmes.

A set of 41 wheat microsatellite markers (WMS), giving 42 polymorphic loci (two loci on each chromosome), was used to describe genetic diversity in a sample of 559 French bread wheat accessions (landraces and registered varieties) cultivated between 1800 and 2000. A total of 609 alleles were detected. Allele number per locus ranged from 3 to 28, with a mean allele number of 14.5. On the average, about 72% of the total number of alleles were observed with a frequency of less than 5% and were considered to be rare alleles. WMS markers used showed different levels of gene diversity: the highest PIC value occurred in the B genome (0.686) compared to 0.641 and 0.659 for the A and D genomes, respectively. When comparing landraces with registered varieties gathered in seven temporal groups, a cluster analysis based on an F(st) matrix provided a clear separation of landraces from the seven variety groups, while a shift was observed between varieties registered before and after 1970. There was a decrease of about 25% in allelic richness between landraces and varieties. In contrast, when considering only registered varieties, changes in diversity related to temporal trends appeared more qualitative than quantitative, except at the end of the 1960s, when a bottleneck might have occurred. New varieties appear to be increasingly similar to each other in relation to allelic composition, while differences between landraces are more and more pronounced over time. Finally, considering a sub-sample of 193 varieties representative of breeding material selected during the twentieth century by the six most important plant breeding companies, few differences in diversity were observed between the different breeding programmes. The observed structure of diversity in French bread wheat collections is discussed in terms of consequences, both for plant breeders and for managers of crop genetic resources.

Alleles↗

Genomic prediction-aided incorporation of genetic resources into elite breeding: lessons from a collaborative multiparental design in flint maize.

A public private cooperative mating design between elite maize inbred lines and diversity donors shows that genomic prediction holds great promise to improve the use of genetic resources. Genetic diversity is essential for plant breeding, enabling long-term gains and adaptation to climate change and new agronomical practices. Breeders can access diverse genetic resources to enhance elite germplasm and introduce new favorable variations. The limited performance of genetic resources may hamper their use. To overcome this, a bridging population can be implemented to evaluate and select progenies from crosses between diversity donors and elite lines before their introduction in breeding programs. The choice of such crosses can be dealt with the usefulness criterion (UC), which determines its ability to produce transgressive individuals. This paper investigates the use of genome-wide marker effects to predict (i) the performance of individuals derived from crosses between donors and elite lines and (ii) the UC of crosses not observed yet. It also compares donor introduction strategies based on the UC or the H criterion, which considers the genome-wide donor-elite complementarity. We used a flint maize collaborative multi-parental BC1-S2 population, consisting in materials from six breeding companies and one public institute crossed to different donors. The 20 crosses had contrasted means and genetic variances, and most of them presented transgressive individuals above the elite parent. Results emphasize the importance of half-siblings derived from the elite line parent of the predicted cross to efficiently predict progeny performances or the UC. They also showed that using the H criterion appears promising to select iteratively donors that best complement initial elite materials. The paper concludes with guidelines for implementing a bridging population using genome-wide marker-based predictions.

Zea mays↗

Genetic improvement of the somatic embryogenesis and regeneration in soybean and transformation of the improved breeding lines.

Somatic embryos of soybean [Glycine max (L.) Merrill] have been used to generate transgenic plants by particle bombardment. The induction and proliferation of somatic embryos from immature cotyledons are dependent on the genotype of the cultivar. Whereas somatic embryogenesis and plant regeneration are inefficient in most cultivars, they are efficient in the cultivar Jack. We previously established a breeding line, QF2, by the integration of null mutations of each subunit of the major seed storage proteins glycinin and beta-conglycinin, but the embryogenic response of this line is insufficient to allow efficient transformation. We have now backcrossed QF2 to cultivar Jack in order to combine the null traits with competence for somatic embryogenesis. The backcrossed breeding lines selected on the basis of the absence of the major storage proteins exhibited an improved capacity for the induction and proliferation of somatic embryos compared with that of QF2. The induced somatic embryogenic tissue of these breeding lines was successfully used for the production of transgenic plants by particle bombardment. These results also indicate that somatic embryogenesis in soybean is genetically controlled and inherited in a manner independent of the null traits of the major seed storage proteins.

Antigens, Plant↗

From genetical genomics to systems genetics: potential applications in quantitative genomics and animal breeding.

This article reviews methods of integration of transcriptomics (and equally proteomics and metabolomics), genetics, and genomics in the form of systems genetics into existing genome analyses and their potential use in animal breeding and quantitative genomic modeling of complex traits. Genetical genomics or the expression quantitative trait loci (eQTL) mapping method and key findings in this research are reviewed. Various procedures and potential uses of eQTL mapping, global linkage clustering, and systems genetics are illustrated using actual analysis on recombinant inbred lines of mice with data on gene expression (for diabetes- and obesity-related genes), pathway, and single nucleotide polymorphism (SNP) linkage maps. Experimental and bioinformatics difficulties and possible solutions are discussed. The main uses of this systems genetics approach in quantitative genomics were shown to be in refinement of the identified QTL, candidate gene and SNP discovery, understanding gene-environment and gene-gene interactions, detection of candidate regulator genes/eQTL, discriminating multiple QTL/eQTL, and detection of pleiotropic QTL/eQTL, in addition to its use in reconstructing regulatory networks. The potential uses in animal breeding are direct selection on heritable gene expression measures, termed "expression assisted selection," and genetical genomic selection of both QTL and eQTL based on breeding values of the respective genes, termed "expression-assisted evaluation."

Animals↗

Genetic variability assessed by microsatellites in a breeding program of Pacific white shrimp (Litopenaeus vannamei).

Genetic diversity in a shrimp-breeding program was monitored for 2 generations by microsatellite DNA markers (Pvan1578 and Pvan1815) to establish levels of variation and proceed with a selection program. An increase in the number and frequencies of some alleles in both microsatellite loci from G0 to G2 was induced by foreign sire contributions. Most common alleles and high heterozygosities (around 70% in both loci) were maintained through the generations, indicating that there had not been a significant loss of genetic variability in the breeding program. However, when compared with variability in other wild and cultured stocks, the presence of 4 main alleles at both loci may be an indication that a certain reduction in variability already was present in the line used as founder stock (G0). Therefore, it is recommended that additional genetic variability be introduced to the breeding stock by crossing it with a different line.

Animals↗

Development of a grassland integrity index based on breeding bird assemblages.

We utilized landscape and breeding bird assemblage data from three Breeding Bird Survey (BBS) routes sampled from 1965-1995 to develop and test a grassland integrity index (GII) in a mixed-grass prairie area of Oklahoma. The overall study region is extensively fragmented from long-term agricultural activity, and native habitat remnants have been degraded by recent encroachment of woody vegetation, namely eastern red cedar (Juniperus virginiana L.). The 50 individual bird survey points along the BBS routes, known as stops, were used as sample sites. Our process first focused on developing a grassland disturbance index (GDI) as a measure of cumulative landscape disturbances for these sites. The GDI was based on five key landscape variables identified in an earlier species-level study of long-term avian community dynamics: total tree, shrub, and herbaceous vegetation cover indices, overall mean landscape patch size, and grassland patch core size. The GII was then developed based on breeding bird assemblage data. Assemblages were based on commonly used response guilds reflective of five avian life history parameters: foraging mode/location, nesting location, habitat specificity, migratory pattern, and dietary guild. We tested the response of 78 candidate assemblage metrics to the GDI, and eliminated those with no or poor response or with high correlations (redundant), resulting in 13 metrics for use in the final index. Individual metric scores were scaled to fall between 0 and 10, and the cumulative index to range from 0 to 100. Although broader application and refinement are possible, the avian-based GII has an advantage over labor-intensive, habitat-based monitoring in that the GII is derived from readily available long-term BBS data. Therefore, the GII shows promise as an inexpensive tool that could easily be applied over other areas to monitor changes in regional grassland conditions.

Agriculture↗