Resistance and Aerobic Training Were Effective in Activating Different Markers of the Browning Process in Obesity

Lifestyle changes regarding diet composition and exercise training have been widely used as a non-pharmacological clinical strategy in the treatment of obesity, a complex and difficult-to-control disease. Taking the potential of exercise in the browning process and in increasing thermogenesis into account, the aim of this paper was to evaluate the effect of resistance, aerobic, and combination training on markers of browning of white adipose tissue from rats with obesity who were switched to a balanced diet with normal calorie intake. Different types of training groups promote a reduction in the adipose tissue and delta mass compared to the sedentary high-fat diet group (HS). Interestingly, irisin in adipose tissues was higher in the resistance exercise (RE) and aerobic exercise (AE) groups compared to control groups. Moreover, in adipose tissue, the fibroblast growth factor 21 (FGF21), coactivator 1 α (PGC1α), and peroxisome proliferator-activated receptor gamma (PPARγ) were higher in response to resistance training RE compared with the control groups, respectively. Additionally, uncoupling protein 1 (UCP1) showed higher levels in response to group AE compared to the HS group. In conclusion, the browning process in white adipose tissue responds differently toward different training exercise protocols, with resistance and aerobic training efficient in activating different biomarkers of the browning process, upregulating irisin, FGF21, PGC1α, PPARγ, and UCP1 in WAT, which together may suggest an improvement in the thermogenic process in the adipose tissue. Considering the experimental conditions of the present investigation, we suggest future research to pave new avenues to be applied in clinical practices to combat obesity.

Additional evidence supports GRM6 p.Thr178Met as a cause of congenital stationary night blindness in three horse breeds

Congenital stationary night blindness (CSNB) is an ocular disorder characterized by nyctalopia. An autosomal recessive missense mutation in glutamate metabotropic receptor 6 (GRM6 c.533C>T, p.(Thr178Met)), called CSNB2, was previously identified in one Tennessee Walking Horse and predicted to reduce binding affinity of the neurotransmitter glutamate, impacting the retinal rod ON-bipolar cell signaling pathway. Thus, the first aim was to identify the allele frequency (AF) of CSNB2 in breeds with reported cases of CSNB and breeds closely related to the Tennessee Walking Horse. The second aim was to perform ocular examinations in multiple breeds to confirm the link between genotype and CSNB phenotype. In evaluating 3518 horses from 14 breeds, the CSNB2 allele was identified in nine previously unreported breeds. The estimated AF was highest in pacing Standardbreds (0.17) and lowest in American Quarter Horses (0.0010). Complete ophthalmic examinations and electroretinograms (ERG) were performed on 19 horses from three breeds, including one CSNB2 homozygote from each breed. All three CSNB2/CSNB2 horses had an electronegative ERG waveform under scotopic light conditions consistent with CSNB. The remaining 16 horses (seven CSNB2/N and nine N/N) had normal scotopic ERG results. All horses had normal photopic ERGs. This study provides additional evidence that GRM6 c.533C>T homozygosity is likely causal to CSNB in Tennessee Walking Horses, Standardbreds, and Missouri Fox Trotting Horses. Genetic testing is recommended for breeds with the CSNB2 allele to limit the production of affected horses. This study represents the largest across-breed identification of CSNB in the horse and suggests that this disorder is likely underdiagnosed.

Short report: Experiences of Caregivers Participating in a Telehealth Evaluation of Development for Infants (TEDI)

A growing literature supports the feasibility and validity of telehealth-based assessments for autism spectrum disorder (ASD). Better understanding families' experiences is crucial for sustained use beyond the COVID-19 pandemic. This study qualitatively examines caregiver experiences with the Telehealth Evaluation of Development for Infants (TEDI) protocol to better understand benefits and challenges of telehealth-based evaluations. Caregivers (N = 32) completed an online survey following a telehealth-based evaluation with their 6-12 month-old infants. Open-ended text responses to queries about perceived benefits, challenges, and suggestions for future adaptations were coded. Most caregivers reported positive experiences with minor feedback relating to tailoring of individual needs. Responses suggest the TEDI is a feasible approach and provide guidance for components of successful telehealth evaluations more broadly.

Analysis of Genetic Diversity in the American Standardbred Horse Utilizing Short Tandem Repeats and Single Nucleotide Polymorphisms

American Standardbreds were developed as a harness racing horse breed. The United States Trotting Association closed the studbook in 1973 and implemented a book size cap in 2009. This study aimed to investigate genetic diversity in the American Standardbred after the studbook cap was introduced using short tandem repeats (STRs) and single-nucleotide polymorphisms (SNPs). Sixteen STRs from horses foaled from 2010 to 2015 and their sires and dams (n = 50 621) were utilized to examine allelic richness (A_r), expected heterozygosity (H_E), observed heterozygosity (H_O), unbiased heterozygosity (H_U), inbreeding coefficient (F_IS), and fixation index (F_ST). These analyses found that trotting and pacing sires were less genetically diverse than dams (H_EP_Bonferroni = 0.029 and 6.3 × 10⁻⁵, respectively) and their offspring (A_rP_Bonferroni = 0.034 and 6.9 × 10^-6, respectively), and pacing offspring were significantly less diverse than their dams (H_EP_Bonferroni = 2 × 10^-3). Inbreeding coefficients for trotters (F_IS = −0.014) and pacers (F_IS = −0.012) suggest that breeding practices have maintained diversity. Moderate levels of genetic differentiation (0.066 < F_ST < 0.11) were found between pacing and trotting groups. Additionally, 10 of the most prolific trotting sires and their male offspring (n = 84) were genotyped on the 670K Axiom Equine HD Array. H_O values higher than H_E (P < 0.001), low inbreeding coefficients (mean F = −0.064), and mean F_ROH = 21% indicate relatively high levels of diversity in this cohort, further supporting the STR data. However, in contrast, H_O values were higher for trotting sires (0.41) than their offspring (0.36). This observation warrants further monitoring of diversity over time. These data provide an updated foundation of diversity indices for further, long-term analysis in the breed.

Inflammatory response of the peripheral neuroendocrine system following downhill running

Exploring the relationship between exercise inflammation and the peripheral neuroendocrine system is essential for understanding how acute or repetitive bouts of exercise can contribute to skeletal muscle adaption. In severe damage, some evidence demonstrates that peripheral neuroendocrine receptors might contribute to inflammatory resolution, supporting the muscle healing process through myogenesis. In this sense, the current study aimed to evaluate two classic peripheral neuronal receptors along with skeletal muscle inflammation and adaptation parameters in triceps brachii after exercise. We euthanized C57BL (10 to 12 weeks old) male mice before, and one, two, and three days after a downhill running protocol. The positive Ly6C cells, along with interleukin-6 (IL-6), nuclear factor kappa B (NF-κB), glucocorticoid receptor (GR), α7 subunits of the nicotinic acetylcholine receptor (nAChRs), and myonuclei accretion were analyzed. Our main results demonstrated that nAChRs increased with the inflammatory and myonuclei accretion responses regardless of NF-κB and GR protein expression. These results indicate that increased nAChR may contribute to skeletal muscle adaption after downhill running in mice.

Generation of a Biobank From Two Adult Thoroughbred Stallions for the Functional Annotation of Animal Genomes Initiative

Following the successful creation of a biobank from two adult Thoroughbred mares, this study aimed to recapitulate sample collection in two adult Thoroughbred stallions as part of the Functional Annotation of the Animal Genome (FAANG) initiative. Both stallions underwent thorough physical, lameness, neurologic, and ophthalmic (including electroretinography) examinations prior to humane euthanasia. Epididymal sperm was recovered from both stallions immediately postmortem and cryopreserved. Aseptically collected full thickness skin biopsies were used to isolate, culture and cryopreserve dermal fibroblasts. Serum, plasma, cerebrospinal fluid, urine, and gastrointestinal content from various locations were collected and cryopreserved. Under guidance of a board-certified veterinary anatomic pathologist, 102 representative tissue samples were collected from both horses. Whole tissue samples were flash-frozen and prioritized tissues had nuclei isolated and cryopreserved. Spatially contemporaneous samples of each tissue were submitted for histologic examination. Antemortem and gross pathologic examination revealed mild abnormalities in both stallions. One stallion (ECA_UCD_AH3) had unilateral thoracic limb lameness and bilateral chorioretinal scars. The second stallion (ECA_UCD_AH4) had subtle symmetrical pelvic limb ataxia, symmetrical prostatomegally, and moderate gastrointestinal nematodiasis. DNA from each was whole-genome sequenced and genotyped using the GGP Equine 70K SNP array. The genomic resources and banked biological samples from these animals augments the existing resource available to the equine genomics community. Importantly we may now improve the resolution of tissue-specific gene regulation as affected by sex, as well as add sex-specific tissues and gametes.

Brainstem auditory evoked responses and bone conduction assessment in alpacas

Auditory loss has been reported in camelids using brainstem auditory evoked responses (BAER). Differentiation between conductive versus sensorineural dysfunction has not been investigated. Therefore, the objective of the study was to investigate auditory function using BAER and bone conduction (BC). Twenty-four alpacas: 15 females, 9 intact males (2-16 years of age) were included in a randomized clinical trial. BAER and BC were recorded using two derivations (vertex to mastoid and vertex to cranial aspect of second cervical vertebra). All alpacas underwent complete physical examinations and were sedated with xylazine hydrochloride at 0.6 mg/kg IM. Peaks, when present, were identified and latencies, amplitudes, and amplitude ratios were determined. Eleven alpacas had normal responses and 13 had auditory loss based on BAER. The latter consisted of complete absence of peaks bilaterally (n = 3), absence of peaks unilaterally (n = 1), delayed latencies bilaterally (n = 4), and delayed latencies unilaterally (n = 5). Distinct peaks on BC supported conductive auditory loss in 6 alpacas, difficult to interpret due to stimulus artifact and additional undefined peaks in 4, and absent peaks in 3 alpacas. The cause of auditory loss was presumed to be due to otitis in 6, aging in 4 (10-16 years old), and congenital sensorineural (absent peaks on BAER and BC) in 3 alpacas with unpigmented fiber and irises. BAER and BC are useful and non-invasive to perform techniques for the investigation of auditory loss in alpacas, and further characterization as conductive or sensorineural.

Phenolic composition, antioxidant capacity and α-glucosidase inhibitory activity of raw and boiled Chilean Araucaria araucana kernels

The Araucaria araucana kernels are a traditional food in southern Chile and Argentina. The aim of this work was to determine the composition of the phenolic-enriched extracts (PEEs) of the boiled kernels as well as their antioxidant capacity, inhibitory activity on metabolic syndrome-associated enzymes and effect on postprandial oxidative stress in a simulated gastric digestion model. The PEEs composition was assessed by HPLC-DAD-MS/MS. The main PEEs constituents were catechin and epicatechin in the unbound form, while hydroxybenzoic acids occurred mainly in the bound form. The unbound phenolics from boiled kernels showed significant correlations with DPPH, FRAP, TEAC (Pearson's r of 0.481, 0.331 and 0.417, respectively) and lipid peroxidation (r = 0.381) and were more active than the bound phenolics. The extracts were highly active against α-glucosidase (IC₅₀: 0.33-3.15 µg/mL) and reduced lipoperoxidation. Traditional processing increases the flavan-3-ol content. Our results suggest that this traditional food has potential health promoting properties.

Whole genome sequencing identified a 16 kilobase deletion on ECA13 associated with distichiasis in Friesian horses

BACKGROUND

Distichiasis, an ocular disorder in which aberrant cilia (eyelashes) grow from the opening of the Meibomian glands of the eyelid, has been reported in Friesian horses. These misplaced cilia can cause discomfort, chronic keratitis, and corneal ulceration, potentially impacting vision due to corneal fibrosis, or, if secondary infection occurs, may lead to loss of the eye. Friesian horses represent the vast majority of reported cases of equine distichiasis, and as the breed is known to be affected with inherited monogenic disorders, this condition was hypothesized to be a simply inherited Mendelian trait.

RESULTS

A genome wide association study (GWAS) was performed using the Axiom 670 k Equine Genotyping array (MNEc670k) utilizing 14 cases and 38 controls phenotyped for distichiasis. An additive single locus mixed linear model (EMMAX) approach identified a 1.83 Mb locus on ECA5 and a 1.34 Mb locus on ECA13 that reached genome-wide significance (pcorrected = 0.016 and 0.032, respectively). Only the locus on ECA13 withstood replication testing (p = 1.6 × 10- 5, cases: n = 5 and controls: n = 37). A 371 kb run of homozygosity (ROH) on ECA13 was found in 13 of the 14 cases, providing evidence for a recessive mode of inheritance. Haplotype analysis (hapQTL) narrowed the region of association on ECA13 to 163 kb. Whole-genome sequencing data from 3 cases and 2 controls identified a 16 kb deletion within the ECA13 associated haplotype (ECA13:g.178714_195130del). Functional annotation data supports a tissue-specific regulatory role of this locus. This deletion was associated with distichiasis, as 18 of the 19 cases were homozygous (p = 4.8 × 10- 13). Genotyping the deletion in 955 horses from 54 different breeds identified the deletion in only 11 non-Friesians, all of which were carriers, suggesting that this could be causal for this Friesian disorder.

CONCLUSIONS

This study identified a 16 kb deletion on ECA13 in an intergenic region that was associated with distichiasis in Friesian horses. Further functional analysis in relevant tissues from cases and controls will help to clarify the precise role of this deletion in normal and abnormal eyelash development and investigate the hypothesis of incomplete penetrance.

Whole-genome sequencing identifies missense mutation in GRM6 as the likely cause of congenital stationary night blindness in a Tennessee Walking Horse

BACKGROUND

The only known genetic cause of congenital stationary night blindness (CSNB) in horses is a 1378 bp insertion in TRPM1. However, an affected Tennessee Walking Horse was found to have no copies of this variant.

OBJECTIVES

To identify the genetic cause for CSNB in an affected Tennessee Walking Horse.

STUDY DESIGN

Case report detailing a whole-genome sequencing (WGS) approach to identify a causal variant.

METHODS

A complete ophthalmic exam, including an electroretinogram (ERG), was performed on suspected CSNB-affected horse. WGS data were generated from the case and compared with data from seven other breeds (n = 29). One hundred candidate genes were evaluated for coding variants homozygous in the case and absent in all other horses. Protein modelling was used to assess the functional effects of the identified variant. A random cohort of 90 unrelated Tennessee Walking Horses and 273 horses from additional breeds were screened to estimate allele frequency of the GRM6 variant.

RESULTS

ERG results were consistent with CSNB. WGS analysis identified a missense mutation in metabotropic glutamate receptor 6 (GRM6) (c.533C>T p.Thr178Met). This single nucleotide polymorphism (SNP) is predicted to be deleterious and protein modelling supports impaired binding of the neurotransmitter glutamate. This variant was not detected in 273 horses from three additional breeds. The estimated allele frequency in Tennessee Walking Horses is 10%.

MAIN LIMITATIONS

Limited phenotype information for controls and no additional cases with which to replicate this finding.

CONCLUSIONS

We identified a likely causal recessive missense variant in GRM6. Based on protein modelling, this variant alters GRM6 binding, and thus signalling from the retinal rod cell to the ON-bipolar cell, impairing vision in low light conditions. Given the 10% population allele frequency, it is likely that additional affected horses exist in this breed and further work is needed to identify and examine these animals.

Genetic Testing in the Horse

Genetic testing in horses began in the 1960s, when parentage testing using blood group markers became the standard. In the 1990s, parentage testing shifted from evaluating blood groups to DNA testing. The development of genetics and genomics in both human and veterinarian medicine, along with continued technological advances in the last 2 decades, has helped unravel the causal variants for many horse traits. Genetic testing is also now possible for a variety of phenotypic and disease traits and is used to assist in breeding and clinical management decisions. This article describes the genetic tests that are currently available for horses.

Skeletal muscles induce recruitment of Ly6C+ macrophage subtypes and release inflammatory cytokines 3 days after downhill exercise

Macrophages are one of the most versatile cells of the immune system that can express distinct subtypes and functions depending on the physiological challenge. After skeletal muscle damage, inflammatory macrophage subtypes aid muscles to regenerate and are implicated in physical training adaption. Based on this information, this study aimed to evaluate two classic mice macrophage subtypes and determine whether some inflammatory cytokines might be involved in the muscle adaption process after exercise. For this purpose, mice were exposed to an intermittent experimental protocol of downhill exercise (18 bouts of running, each bout 5 min with a 2-min rest interval, slope -16°) and were euthanized before [control (CTRL)] and 1, 2 (D2), and 3 (D3) days after exercise. After euthanasia, the triceps brachii was harvested and submitted to protein extraction, immunostaining, and mononuclear digestion procedures. The muscle size, macrophage accumulation, and cytokines were determined. We observed an increase in the Ly6C⁺ macrophage subtype (P ≤ 0.05) in D2 and D3 compared with CTRL, as well as a significant inverse correlation coefficient (-0.52; P ≤ 0.05) between Ly6C⁺ and Ly6C^- macrophage subtypes. Moreover, we also observed elevation in several cytokines (IL-1β, IFN-γ, TNF-α, IL-6, and IL-13) at D3, although not IL-4, which tended to decrease at this time point (P = 0.06). Downhill exercises preferentially recruited Ly6C⁺ macrophages with important proinflammatory cytokine elevation at D3. Moreover, despite the elevation of several cytokines involved with myogenesis, an increase in IL-6 and IL-13, which potentially involve muscle adaption training after acute exercise, was also observed.

An Autosomal Translocation 73,XY,t(12;20)(q11;q11) in an Infertile Male Llama (Lama glama) With Teratozoospermia

Structural chromosome abnormalities, such as translocations and inversions occasionally occur in all livestock species and are typically associated with reproductive and developmental disorders. Curiously, only a few structural chromosome aberrations have been reported in camelids, and most involved sex chromosomes. This can be attributed to a high diploid number (2n = 74) and complex chromosome morphology, which makes unambiguous identification of camelid chromosomes difficult. Additionally, molecular tools for camelid cytogenetics are sparse and have become available only recently. Here we present a case report about an infertile male llama with teratozoospermia and abnormal chromosome number 2n = 73,XY. This llama carries an autosomal translocation of chromosomes 12 and 20, which is the likely cause of defective spermatogenesis and infertility in this individual. Our analysis underlines the power of molecular cytogenetics methods over conventional banding-based chromosome analysis for explicit identification of normal and aberrant chromosomes in camelid karyotypes. This is the first case of a translocation and the first autosomal aberration reported in any camelid species. It is proof of principle that, like in other mammalian species, structural chromosome abnormalities contribute to reproductive disorders in camelids.

Evaluation of an HMGA2 variant for pleiotropic effects on height and metabolic traits in ponies

BACKGROUND

Ponies are highly susceptible to metabolic derangements including hyperinsulinemia, insulin resistance, and adiposity.

HYPOTHESIS/OBJECTIVES

Genetic loci affecting height in ponies have pleiotropic effects on metabolic pathways and increase the susceptibility to equine metabolic syndrome (EMS).

ANIMALS

Two hundred ninety-four Welsh ponies and 529 horses.

METHODS

Retrospective study of horses phenotyped for metabolic traits. Correlations between height and metabolic traits were assessed by Pearson's correlation coefficients. Complementary genome-wide analysis methods were used to identify a region of interest (ROI) for height and metabolic traits, determine the fraction of heritability contributed by the ROI, and identify candidate genes.

RESULTS

There was an inverse relationship between height and baseline insulin (-0.26) in ponies. Genomic signature of selection and association analyses for both height and insulin identified the same ~1.3 megabase region on chromosome 6 that contained a shared ancestral haplotype between these traits. The ROI contributed ~40% of the heritability for height and ~20% of the heritability for insulin. High-mobility group AT-hook 2 was identified as a candidate gene, and Sanger sequencing detected a c.83G>A (p.G28E) variant associated with height in Shetland ponies. In our cohort of ponies, the A allele had a frequency of 0.76, was strongly correlated with height (-0.75), and was low to moderately correlated with metabolic traits including: insulin (0.32), insulin after an oral sugar test (0.25), non-esterified fatty acids (0.19), and triglyceride (0.22) concentrations.

CONCLUSIONS AND CLINICAL IMPORTANCE

These data have important implications for identifying individuals at risk for EMS.

Genome-Wide Signatures of Selection Reveal Genes Associated With Performance in American Quarter Horse Subpopulations

Selective breeding for athletic performance in various disciplines has resulted in population stratification within the American Quarter Horse (QH) breed. The goals of this study were to utilize high density genotype data to: (1) identify genomic regions undergoing positive selection within and among QH subpopulations; (2) investigate haplotype structure within each QH subpopulation; and (3) identify candidate genes within genomic regions of interest (ROI), as well as biological pathways, predicted to play a role in elite performance in each group. For that, 65K SNP genotyping data on 143 elite individuals from 6 QH subpopulations (cutting, halter, racing, reining, western pleasure, and working cow) were imputed to 2M SNPs. Signatures of selection were identified using F_ST-based (d_i ) and haplotype-based (hapFLK) analyses, accompanied by identification of local haplotype structure and sharing within subpopulations (hapQTL). Regions undergoing positive selection were identified on all 31 autosomes, and ROI on 2 chromosomes were identified by all 3 methods combined. Genes within each ROI were retrieved and used to identify pathways and genes that might contribute to performance in each subpopulation. These included, among others, candidate genes associated with skeletal muscle development, metabolism, and central nervous system development. This work improves our understanding of equine breed development, and provides breeders with a better understanding of how selective breeding impacts the performance of QH populations.

Comment on “Elucidation of charge-transfer SERS selection rules by considering the excited state properties and the role of electrode potential” by M. Mohammadpour, M. H. Khodabandeh, L. Visscher and Z. Jamshidi, Phys. Chem. Chem. Phys., 2017, 19, 7833

Different theoretical tools for modelling the complex role of the electrode potential in SERS are highlighted.

A Non-Reciprocal Autosomal Translocation 64,XX, t(4;10)(q21;p15) in an Arabian Mare with Repeated Early Embryonic Loss

Balanced autosomal translocations are a known cause for repeated early embryonic loss (REEL) in horses. In most cases, carriers of such translocations are phenotypically normal, but the chromosomal aberration negatively affects gametogenesis giving rise to both genetically balanced and unbalanced gametes. The latter, if involved in fertilization, result in REEL, whereas gametes with the balanced form of translocation will pass the defect into next generation. Therefore, in order to reduce the incidence of REEL, identification of translocation carriers is critical. Here, we report about a phenotypically normal 3-year-old Arabian mare that had repeated resorption of conceptuses prior to day 45 of gestation and was diagnosed with REEL. Conventional and molecular cytogenetic analyses revealed that the mare had normal chromosome number 64,XX but carried a non-mosaic and non-reciprocal autosomal translocation t(4;10)(q21;p15). This is a novel translocation described in horses with REEL and the first such report in Arabians. Previous cases of REEL due to autosomal translocations have exclusively involved Thoroughbreds. The findings underscore the importance of routine cytogenetic screening of breeding animals.

A comprehensive whole-genome integrated cytogenetic map for the alpaca (Lama pacos)

Genome analysis of the alpaca (Lama pacos, LPA) has progressed slowly compared to other domestic species. Here, we report the development of the first comprehensive whole-genome integrated cytogenetic map for the alpaca using fluorescence in situ hybridization (FISH) and CHORI-246 BAC library clones. The map is comprised of 230 linearly ordered markers distributed among all 36 alpaca autosomes and the sex chromosomes. For the first time, markers were assigned to LPA14, 21, 22, 28, and 36. Additionally, 86 genes from 15 alpaca chromosomes were mapped in the dromedary camel (Camelus dromedarius, CDR), demonstrating exceptional synteny and linkage conservation between the 2 camelid genomes. Cytogenetic mapping of 191 protein-coding genes improved and refined the known Zoo-FISH homologies between camelids and humans: we discovered new homologous synteny blocks (HSBs) corresponding to HSA1-LPA/CDR11, HSA4-LPA/CDR31 and HSA7-LPA/CDR36, and revised the location of breakpoints for others. Overall, gene mapping was in good agreement with the Zoo-FISH and revealed remarkable evolutionary conservation of gene order within many human-camelid HSBs. Most importantly, 91 FISH-mapped markers effectively integrated the alpaca whole-genome sequence and the radiation hybrid maps with physical chromosomes, thus facilitating the improvement of the sequence assembly and the discovery of genes of biological importance.

A cytogenetic and comparative map of camelid chromosome 36 and the minute in alpacas

Recent advances in camelid genomics have provided draft sequence assemblies and the first comparative and gene maps for the dromedary (CDR) and the alpaca (LPA). However, no map information is currently available for the smallest camelid autosome-chr36. The chromosome is also of clinical interest because of its involvement in the minute chromosome syndrome (MCS) in infertile alpacas. Here, we developed molecular markers for camelid chr36 by direct sequencing CDR36 and LPA minute and by bioinformatics analysis of alpaca unplaced sequence scaffolds. We constructed a cytogenetic map for chr36 in the alpaca, llama, and dromedary and showed its homology to human chromosome 7 (HSA7) at 49.8-55.5 Mb. The chr36 map comprised seven markers, including two genes-ZPBP and WVC2. Comparative status of HSA7 was further refined by cytogenetic mapping of 16 HSA7 orthologs in camelid chromosomes 7 and 18 and by the analysis of HSA7-conserved synteny blocks across 11 vertebrate species. Finally, mapping chr36 markers in infertile alpacas confirmed that the minute chromosome was a derivative of chr36, but the small size was not a result of a large deletion or a translocation. Instead, cytogenetic mapping of 5.8S, 18S, and 28S rRNA genes (nucleolus organizer region (NOR)) revealed that the size difference between chr36 homologs in infertile alpacas was due to a heterozygous presence of NOR, whereas chr36 in fertile alpacas had no NOR. We theorized that the heterozygous NOR might affect chr36 pairing, recombination, and segregation in meiosis and, thus fertility.

Comparative organization and gene expression profiles of the porcine pseudoautosomal region

The pseudoautosomal region (PAR) has important biological functions in spermatogenesis, male fertility and early development. Even though pig (Sus scrofa, SSC) is an agriculturally and biomedically important species, and its genome is sequenced, current knowledge about the porcine PAR is sparse. Here we defined the PAR in SSCXp/Yp by demarcating the sequence of the pseudoautosomal boundary at X:6,743,567 bp in intron 3-4 of SHROOM2 and showed that SHROOM2 is truncated in SSCY. Cytogenetic mapping of 20 BAC clones containing 15 PAR and X-specific genes revealed that the pig PAR is largely collinear with other mammalian PARs or Xp terminal regions. The results improved the current SSCX sequence assembly and facilitated distinction between the PAR and X-specific genes to study their expression in adult and embryonic tissues. A pilot analysis showed that the PAR genes are expressed at higher levels than X-specific genes during early development, whereas the expression of PAR genes was higher at day 60 compared to day 26, and higher in embryonic tissues compared to placenta. The findings advance the knowledge about the comparative organization of the PAR in mammals and suggest that the region might have important functions in early development in pigs.

Development and application of camelid molecular cytogenetic tools

Cytogenetic chromosome maps offer molecular tools for genome analysis and clinical cytogenetics and are of particular importance for species with difficult karyotypes, such as camelids (2n = 74). Building on the available human-camel zoo-fluorescence in situ hybridization (FISH) data, we developed the first cytogenetic map for the alpaca (Lama pacos, LPA) genome by isolating and identifying 151 alpaca bacterial artificial chromosome (BAC) clones corresponding to 44 specific genes. The genes were mapped by FISH to 31 alpaca autosomes and the sex chromosomes; 11 chromosomes had 2 markers, which were ordered by dual-color FISH. The STS gene mapped to Xpter/Ypter, demarcating the pseudoautosomal region, whereas no markers were assigned to chromosomes 14, 21, 22, 28, and 36. The chromosome-specific markers were applied in clinical cytogenetics to identify LPA20, the major histocompatibility complex (MHC)-carrying chromosome, as a part of an autosomal translocation in a sterile male llama (Lama glama, LGL; 2n = 73,XY). FISH with LPAX BACs and LPA36 paints, as well as comparative genomic hybridization, were also used to investigate the origin of the minute chromosome, an abnormally small LPA36 in infertile female alpacas. This collection of cytogenetically mapped markers represents a new tool for camelid clinical cytogenetics and has applications for the improvement of the alpaca genome map and sequence assembly.

Ovarian dysgenesis in an alpaca with a minute chromosome 36

A 4-year-old female alpaca (Lama pacos [LPA]) was presented to the Oregon State Veterinary Teaching Hospital for failure to display receptive behavior to males. Although no abnormalities were found on physical examination, transrectal ultrasonographic examination of the reproductive tract revealed uterine hypoplasia and ovarian dysgenesis. Cytogenetic analysis demonstrated a normal female 74,XX karyotype with 1 exceptionally small (minute) homologue of autosome LPA36. Chromosome analysis by Giemsa staining and DAPI- and C-banding revealed that the minute LPA36 was submetacentric, AT-rich, and largely heterochromatic. Because of the small size and lack of molecular markers, it was not possible to identify the origin of the minute. There is a need to improve molecular cytogenetic tools to further study the phenomenon of this minute chromosome and its relation to female reproduction in alpacas and llamas.

The pseudoautosomal region and sex chromosome aneuploidies in domestic species

The pseudoautosomal region (PAR) is a unique and specialized segment on the mammalian sex chromosomes with known functions in male meiosis and fertility. Detailed molecular studies of the region in human and mouse show dramatic differences between the 2 PARs. Recent mapping efforts in horse, dog/cat, cattle/ruminants, pig and alpaca indicate that the PAR also varies in size and gene content between other species. Given that PAR genes escape X inactivation, these differences might critically affect the genetic consequences, such as embryonic survival and postnatal phenotypes of sex chromosome aneuploidies. The aim of this review is to combine the available information about the organization of the PAR in domestic species with the cytogenetic data on sex chromosome aneuploidies. We show that viable XO individuals are relatively frequently found in species with small PARs, such as horses, humans and mice but are rare or absent in species in which the PAR is substantially larger, like in cattle/ruminants, dogs, pigs, and alpacas. No similar correlation can be detected between the PAR size and the X chromosome trisomy in different species. Recent evidence about the likely involvement of PAR genes in placenta formation, early embryonic development and genomic imprinting are presented.

Simultaneous chemical and photochemical protein crosslinking induced by irradiation of eye lens proteins in the presence of ascorbate: the photosensitizing role of an UVA-visible-absorbing decomposition product of vitamin C

Exposure to light has been implicated as a risk factor during aging of the eye lens and in cataract generation. In order to visualize the actual effect of UVA-visible light on this tissue, we incubated water-soluble eye lens proteins with ascorbate in the presence and absence of UVA-visible light for 3, 6 and 9 days at low oxygen concentration. The samples incubated in the presence of light were characterized by an initially small but continuous increase over time of the protein crosslinking. This was not the result of more extensive glycation because the decrease in amino group content of the proteins and the decomposition of ascorbate was the same in both irradiated and unirradiated samples. The augmented crosslinking capacity observed in the presence of UVA-visible light is due to the generation of a chromophore from the decomposition of ascorbate. This chromophore, obtained after 3, 6 and 9 days of incubation of solutions containing only ascorbate, induces both protein-crosslinking and oxidation after exposure to UVA-visible light in the presence of lens proteins. The extent of the crosslinking was proportional to the amount of the chromophore present in the solution. The presence of this chromophore was also determined when ascorbate was incubated with four-fold higher concentrations of N-α-acetyl lysine and N-α-acetyl arginine. When these samples were used as photosensitizers, the crosslinking degree was conditioned by the presence of this chromophore; nonetheless, the ascorbate-mediated advanced glycation end product (AGE) generation also made a contribution. The results of this work indicate that ascorbate oxidation, which generates the AGEs responsible for the chemical crosslinking of the lens proteins, also simultaneously produces a chromophore that can act as a photosensitizer, further increasing the protein crosslinking.

[Otitis media with effusion: expectant management]

OBJECTIVE: Despite the fact that chronic otitis media with effusion (OME) is an entity with a high prevalence among children, the real effectiveness of most treatments in use nowadays has not been completely established. Based on its natural course, we defend an expectant management as the initial treatment. METHODS: We undertook a review of the available data taking into consideration the natural history, epidemiology and therapeutic options for OME. We looked for a guideline concerning the best treatment for OME in children. RESULTS: The treatment of OME still remains controversial, in spite of many therapeutic options. In children, the best management still seems to be the observation, probably for a period of three to six months. However, interventionist treatment should be done earlier on those patients considered as high risk or in which a problem happened with their development, due to hearing loss secondary to OME. CONCLUSIONS: The understanding of the several factors involved in the pathogenesis of OME, as well as of the features in its evolutive course, encourage the idea of a conservative expectant approach at first or up to the moment in which an interventionist approach (clinical or surgical) is justified.

Effect of adriamycin on DNA, RNA, and protein synthesis in cell-free systems and intact cells

The effect of adriamycin on DNA, RNA, and protein synthesis was investigated in cell-free systems and intact cells. In studies with purified mammalian cell enzymes, adriamycin produced a greater inhibition of DNA-dependent DNA polymerase than of RNA polymerase. The extent of inhibition of both these enzymes was decreased by increasing the concentration of the DNA template in the reaction mixture. In studies with isolated nuclei, adriamycin was also a more potent inhibitor of DNA synthesis than RNA synthesis. However, with intact cells, adriamycin inhibited both DNA and RNA synthesis to about the same extent. The inhibition produced by adriamycin on RNA synthesis in intact cells was greater than that observed in the cell-free systems. Adriamycin inhibited protein synthesis in a cell-free system consisting of polyribosomes, transfer RNA, and enzymes but did not inhibit protein synthesis in intact cells. These differences in the pattern of inhibition may be due to biotransformation of the drug and/or preferential binding to chromosomal DNA in the intact cell.

Rapid detection of urinary infections by microscopic observation of growing cultures

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