[Adverse events in biologics for severe asthma]

INTRODUCTION

Asthma is a pathology that remains severe and is inadequately controlled in 4% of patients. Identification of multiple pathophysiological mechanisms has led to the development of biomedicines, of which there are currently five available in France, with a safety profile that appears favorable but remains uncertain due to a lack of real-life experience with these new molecules.

STATE OF KNOWLEDGE

Although relatively benign, the adverse effects of biologics are diverse. Headache, joint pain, skin reactions at the injection site, fever and asthenia are commonly observed during the different treatments. Ophthalmological complications seem restricted to dupilumab, with numerous cases of keratitis and conjunctivitis in patients with atopic dermatitis. Several respiratory complications have also been observed, essentially consisting in pharyngitis and other upper respiratory infections. Hypereosinophilia may occur, mainly with dupilumab, requiring investigation of systemic repercussions or vasculitis. Allergic reactions are uncommon but require careful monitoring during initial injections.

CONCLUSION

Biologics for severe asthma are recent drugs with a favorable safety profile, but with little real-life experience, justifying increased vigilance by prescribing physicians.

Quantitative brainstem and spinal MRI in amyotrophic lateral sclerosis: implications for predicting noninvasive ventilation needs

BACKGROUND

Respiratory complications resulting from motor neurons degeneration are the primary cause of death in amyotrophic lateral sclerosis (ALS). Predicting the need for non-invasive ventilation (NIV) in ALS is important for advance care planning and clinical trial design. The aim of this study was to assess the potential of quantitative MRI at the brainstem and spinal cord levels to predict the need for NIV during the first six months after diagnosis.

METHODS

Forty-one ALS patients underwent MRI and spirometry shortly after diagnosis. The need for NIV was monitored according to French health guidelines for 6 months. The performance of four regression models based on: clinical variables, brainstem structures volumes, cervical spinal measurements, and combined variables were compared to predict the need for NIV within this period.

RESULTS

Both the clinical model (R2 = 0.28, AUC = 0.85, AICc = 42.67, BIC = 49.8) and the brainstem structures' volumes model (R2 = 0.30, AUC = 0.85, AICc = 40.13, BIC = 46.99) demonstrated good predictive performance. In addition, cervical spinal cord measurements model similar performance (R2 = 0.338, AUC = 0.87, AICc = 37.99, BIC = 44.49). Notably, the combined model incorporating predictors from all three models yielded the best performance (R2 = 0.60, AUC = 0.959, AICc = 36.38, BIC = 44.8). These findings are supported by observed positive correlations between brainstem volumes, cervical (C4/C7) cross-sectional area, and spirometry-measured lung volumes.

CONCLUSIONS

Our study shows that brainstem volumes and spinal cord area are promising measures to predict respiratory intervention needs in ALS.

[Diaphragmatic ultrasonography for the pulmonologist: Technique and clinical use]

INTRODUCTION

Ultrasonography is an emerging tool that helps to assess diaphragmatic function. It is now widely used in ICUs to predict weaning from mechanical ventilation. Ultrasonography is readily available, harmless (no radiation), and repeatable with good interoperator reproducibility. Over the past few years, ultrasonography has seen increasing use in patients with chronic pulmonary pathologies.

STATE OF THE ART

The aim of this review is (1) to describe the ultrasound techniques used to assess diaphragmatic excursion and thickening, (2) to indicate the expected, normal values in healthy patients, and (3) to summarize the main findings and clinical applications in treatment of chronic respiratory disorders.

CONCLUSIONS

Chronic pulmonary diseases are associated with diaphragmatic dysfunction that can be assessed with ultrasound. Diaphragmatic dysfunction is primary in neuromuscular disorders and secondary to respiratory disease in other chronic pulmonary conditions (COPD, ILD). Ultrasound is correlated with the severity of the underlying disease (functional and clinical parameters).

PERSPECTIVES

The prognostic interest of diaphragm ultrasonography remains to be established, after which its utilization should become routine.

Development, sensitivity and reliability of a French version of the Leeds Food Preference Questionnaire (LFPQ-fr) for the evaluation of food preferences and reward

BACKGROUND

. There is a growing global interest in the evaluation of food reward, necessitating the adaptation of culturally appropriate instruments for use in empirical studies. This work presents the development and validation of a culturally adapted French version of the Leeds Food Preference Questionnaire (LFPQ-fr).

METHODS

. The LFPQ-fr was developed and validated in healthy-weight adults using the following systematic approach: i) selection and validation of appropriate food pictures; ii) linguistic translation of liking and wanting constructs in the target population (n=430; 81% female; 42.2 ± 12.7 years); iii) validation of the sensitivity and reliability of the task performed in a fasted state and in response to a standardized test meal (n=50; 50% female; 30.0 ± 8.4 years).

RESULTS

. During the first and second phases, the nutritional and perceptual validation of culturally appropriate food pictures and pertinent reward constructs, respectively, was demonstrated in a healthy-weight French sample. Findings from the third phase indicated that all food reward components were sensitive to the test meal and showed moderate to high agreement in both fasted (Lin's CCC =.72-.94) and fed (Lin's CCC = .53-.80) appetitive states between visit 1 (V1) and visit (V2). Except for explicit liking fat bias, all primary outcomes were statistically consistent in fasted and fed states between V1 and V2. Changes in fat and taste biases in response to a standardized meal for all primary outcomes were also consistent between V1 and V2 except for explicit liking fat bias (Lin's CCC = .49- .72).

CONCLUSION

. The LFPQ-fr developed and tested in this study is a reproducible and reliable method to assess food reward in both the fasted and fed states in a healthy-weight French population.

Proposals from a French expert panel for respiratory care in ALS patients

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive diaphragm weakness and deteriorating lung function. Bulbar involvement and cough weakness contribute to respiratory morbidity and mortality. ALS-related respiratory failure significantly affects quality of life and is the leading cause of death. Non-invasive ventilation (NIV), which is the main recognized treatment for alleviating the symptoms of respiratory failure, prolongs survival and improves quality of life. However, the optimal timing for the initiation of NIV is still a matter of debate. NIV is a complex intervention. Multiple factors influence the efficacy of NIV and patient adherence. The aim of this work was to develop practical evidence-based advices to standardize the respiratory care of ALS patients in French tertiary care centres.

METHODS

For each proposal, a French expert panel systematically searched an indexed bibliography and prepared a written literature review that was then shared and discussed. A combined draft was prepared by the chairman for further discussion. All of the proposals were unanimously approved by the expert panel.

RESULTS

The French expert panel updated the criteria for initiating NIV in ALS patients. The most recent criteria were established in 2005. Practical advice for NIV initiation were included and the value of each tool available for NIV monitoring was reviewed. A strategy to optimize NIV parameters was suggested. Revisions were also suggested for the use of mechanically assisted cough devices in ALS patients.

CONCLUSION

Our French expert panel proposes an evidence-based review to update the respiratory care recommendations for ALS patients in daily practice.

High male specific contribution of the X-chromosome to individual global recombination rate in dairy cattle

Background

Meiotic recombination plays an important role in reproduction and evolution. The individual global recombination rate (GRR), measured as the number of crossovers (CO) per gametes, is a complex trait that has been shown to be heritable. The sex chromosomes play an important role in reproduction and fertility related traits. Therefore, variants present on the X-chromosome might have a high contribution to the genetic variation of GRR that is related to meiosis and to reproduction.

Results

We herein used genotyping data from 58,474 New Zealand dairy cattle to estimate the contribution of the X-chromosome to male and female GRR levels. Based on the pedigree-based relationships, we first estimated that the X-chromosome accounted for 30% of the total additive genetic variance for male GRR. This percentage was equal to 19.9% when the estimation relied on a SNP-BLUP approach assuming each SNP has a small contribution. We then carried out a haplotype-based association study to map X-linked QTL, and subsequently fine-mapped the identified QTL with imputed sequence variants. With this approach we identified three QTL with large effect accounting for 7.7% of the additive genetic variance of male GRR. The associated effects were equal to + 0.79, − 1.16 and + 1.18 CO for the alternate alleles. In females, the estimated contribution of the X-chromosome to GRR was null and no significant association with X-linked loci was found. Interestingly, two of the male GRR QTL were associated with candidate genes preferentially expressed in testis, in agreement with a male-specific effect. Finally, the most significant QTL was associated with PPP4R3C, further supporting the important role of protein phosphatase in double-strand break repair by homologous recombination.

Conclusions

Our study illustrates the important role the X-chromosome can have on traits such as individual recombination rate, associated with testis in males. We also show that contribution of the X-chromosome to such a trait might be sex dependent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08328-8.

Stray light characterization with ultrafast time-of-flight imaging

Understanding stray light (SL) is a crucial aspect in the development of high-end optical instruments, for instance space telescopes. As it drives image quality, SL must be controlled by design and characterized experimentally. However, conventional SL characterization methods are limited as they do not provide information on its origins. The problem is complex due to the diversity of light interaction processes with surfaces, creating various SL contributors. Therefore, when SL level is higher than expected, it can be difficult to determine how to improve the system. We demonstrate a new approach, ultrafast time-of-flight SL characterization, where a pulsed laser source and a streak camera are used to record individually SL contributors which travel with a specific optical path length. Furthermore, the optical path length offers a means of identification to determine its origin. We demonstrate this method in an imaging system, measuring and identifying individual ghosts and scattering components. We then show how it can be used to reverse-engineer the instrument SL origins.

[Sclerosing pneumocytoma: A rare and benign tumor]

INTRODUCTION

Sclerosing pneumocytoma is a benign and rare lung tumor affecting epithelial cells. In most cases, patients are asymptomatic and the diagnosis is made on an X ray or a CT scan performed for other enquiry. Sex ratio favors women. Epidemiological studies report that middle-aged Asian women are more frequently affected. Radiological investigations find a solitary nodule or a mass with peripheric localization. When performed, histological analysis shows a tumor composed of at least two of the four following architectures: papillary, sclerosing, hemangiomatous and solid, with two types of cells that can be round or cubic cells.

CASES REPORT

We report two cases of multiple sclerosing pneumocytoma in two caucasien men. The first patient was asymptomatic, the second complain from moderate dyspnea. A wedge resection was performed in both, allowing diagnosis. Anatomopathology revealed respectively a predominant sclerosing and solid architecture and a sclerosing and papillary architecture. There was no progression of the other concomitant nodules after three years follow-up.

CONCLUSION

Pneumocytoma is a benign, slow-growing tumor with good prognosis.

Bilateral vocal cord paralysis after endoscopic placement of fully covered self-expandable metal stent for palliative treatment of malignant proximal esophageal obstruction: two case reports

Background

Oesophageal stents have several well-known respiratory complications, including aspiration pneumonia, fistula and airway compression. However, bilateral vocal cord paralysis has rarely been described.

Methods

We describe two patients who presented with refractory dysphagia due to malignant proximal oesophageal strictures. Both received palliative treatment consisting of fully covered self-expandable metal stents that were placed across the strictures.

Results

Both patients developed inspiratory stridor and acute hypoxemic respiratory failure shortly after the stent was placed. Flexible bronchoscopy revealed vocal cord paralysis in paramedian position, potentially due to extrinsic compression of the posterior branch of the recurrent laryngeal nerve following the progressive opening of the esophageal prosthesis. One patient recovered after the stent was removed.

Conclusions

Bilateral vocal cord paralysis is a rare but potentially fatal complication of proximal esophagus stenting.

Sinonasal mucosal melanoma: A 44-case study and literature analysis

OBJECTIVES

Sinonasal mucosal melanoma is a rare disease, representing 4% of nasal cavity and paranasal sinus malignancies. The aim of this study was to assess the clinical characteristics, progression and treatment of this disease and to identify prognostic factors.

MATERIAL AND METHODS

This retrospective review presents a cohort of 44 patients treated for a melanoma arising from the nasal cavity and paranasal sinuses, in the ENT Head and Neck Surgery Department of the University Hospital of Nantes (France) between 1988 and 2015.

RESULTS

Mean age at diagnosis was 71.2 years. The main signs at diagnosis were epistaxis and unilateral nasal obstruction. 25% of patients were initially classified as T4. Surgical treatment was performed in 42 patients. Postoperative radiotherapy was performed in 19 cases and adjuvant immunotherapy in 14 cases. Mean follow-up was 50 months. Cumulative overall survival was 71.5% at 1 year and 33% at 5 years. Clinically, headache, facial pain and trigeminal V2 nerve anesthesia were significant factors for poor prognosis. Exclusively nasal involvement was a factor for better overall survival than sinus involvement. Adjuvant radiation therapy showed a non-significant trend toward improved local control.

CONCLUSIONS

Mucosal melanoma of the sinonasal cavities has poor prognosis due to high metastatic potential. Surgical resection followed by radiation therapy is the main treatment. There is no consensus regarding new systemic adjuvant treatments in this indication, unlike for primary cutaneous melanoma.

Genome-Wide Association Study of Acute Renal Graft Rejection

Acute renal rejection is a major risk factor for chronic allograft dysfunction and long-term graft loss. We performed a genome-wide association study to detect loci associated with biopsy-proven acute T cell-mediated rejection occurring in the first year after renal transplantation. In a discovery cohort of 4127 European renal allograft recipients transplanted in eight European centers, we used a DNA pooling approach to compare 275 cases and 503 controls. In an independent replication cohort of 2765 patients transplanted in two European countries, we identified 313 cases and 531 controls, in whom we genotyped individually the most significant single nucleotide polymorphisms (SNPs) from the discovery cohort. In the discovery cohort, we found five candidate loci tagged by a number of contiguous SNPs (more than five) that was never reached in iterative in silico permutations of our experimental data. In the replication cohort, two loci remained significantly associated with acute rejection in both univariate and multivariate analysis. One locus encompasses PTPRO, coding for a receptor-type tyrosine kinase essential for B cell receptor signaling. The other locus involves ciliary gene CCDC67, in line with the emerging concept of a shared building design between the immune synapse and the primary cilium.

Breed differences in natriuretic peptides in healthy dogs

BACKGROUND

Measurement of plasma concentration of natriuretic peptides (NPs) is suggested to be of value in diagnosis of cardiac disease in dogs, but many factors other than cardiac status may influence their concentrations. Dog breed potentially is 1 such factor.

OBJECTIVE

To investigate breed variation in plasma concentrations of pro-atrial natriuretic peptide 31-67 (proANP 31-67) and N-terminal B-type natriuretic peptide (NT-proBNP) in healthy dogs.

ANIMALS

535 healthy, privately owned dogs of 9 breeds were examined at 5 centers as part of the European Union (EU) LUPA project.

METHODS

Absence of cardiovascular disease or other clinically relevant organ-related or systemic disease was ensured by thorough clinical investigation. Plasma concentrations of proANP 31-67 and NT-proBNP were measured by commercially available ELISA assays.

RESULTS

Overall significant breed differences were found in proANP 31-67 (P < .0001) and NT-proBNP (P < .0001) concentrations. Pair-wise comparisons between breeds differed in approximately 50% of comparisons for proANP 31-67 as well as NT-proBNP concentrations, both when including all centers and within each center. Interquartile range was large for many breeds, especially for NT-proBNP. Among included breeds, Labrador Retrievers and Newfoundlands had highest median NT-proBNP concentrations with concentrations 3 times as high as those of Dachshunds. German Shepherds and Cavalier King Charles Spaniels had the highest median proANP 31-67 concentrations, twice the median concentration in Doberman Pinschers.

CONCLUSIONS AND CLINICAL IMPORTANCE

Considerable interbreed variation in plasma NP concentrations was found in healthy dogs. Intrabreed variation was large in several breeds, especially for NT-proBNP. Additional studies are needed to establish breed-specific reference ranges.

Genetic diversity of four Filipino negrito populations from Luzon: comparison of male and female effective population sizes and differential integration of immigrants into Aeta and Agta communities

Genetic data corresponding to four negrito populations (two Aeta and two Agta; n = 120) from the Luzon region of the Philippines have been analyzed. These data comprise mitochondrial DNA (mtDNA) hypervariable segment 1 haplotypes and haplogroups, Y-chromosome haplogroups and short tandem repeats (STRs), autosomal STRs, and X-chromosome STRs. The genetic diversity and structure of the populations were investigated at a local, regional, and interregional level. We found a high level of autosomal differentiation, combined with no significant reduction in diversity, consistent with long-term settlement of the Luzon region by the ancestors of the Agta and Aeta followed by reduced gene flow between these two ethnolinguistic groups. Collectively, the Aeta have a much higher ratio of female:male effective population size than do the Agta, a finding that supports phylogenetic analysis of their mtDNA and Y-chromosome haplogroups, which suggests different genetic sex-biased contributions from putative Austronesian source populations. We propose that factors of social organization that led to the reduction in Agta female effective population size may also be linked to the limited incorporation of female lineages associated with the settlement of the Philippines by Austronesian speakers; conversely, the reduction in Aeta male effective population size, relative to females, could be indicative of a limited incorporation of male lineages associated with this demographic process.

Identifying cows with subclinical mastitis by bulk single nucleotide polymorphism genotyping of tank milk

Mastitis remains the most important health issue in dairy cattle. Improved methods to identify cows developing subclinical mastitis would benefit farmers. We herein describe a novel method to determine the somatic cell counts (SCC) of individual cows by bulk genotyping a sample of milk from the milk tank with panels of genome-wide single nucleotide polymorphisms (SNP). We developed a simple linear model to estimate the contribution of individual cows to the genomic DNA present in the tank milk from 1) the known genotypes of individual cows for the interrogated SNP and 2) the ratio of SNP alleles in the tank milk. Using simulations, we estimate that 3,000, 50,000, and 700,000 SNP are sufficient to accurately (R(2)>0.98) estimate individual SCC in tanks containing milk from 25, 100, and 500 cows, respectively. Using actual data, we demonstrate that the SCC of 21 cows can be estimated with a coefficient of determination of 0.60 using approximately 9,000 SNP. The proposed method increases the value of the proposition of SNP genotyping individual cows for genomic selection purposes.

The effect of enterotoxigenic Escherichia coli F4ab,ac on early-weaned piglets: a gene expression study

Diarrhoea in neonatal and early-weaned piglets due to enterotoxigenic Escherichia coli-F4 (ETEC-F4) is an important problem in the pig farming industry. There is substantial evidence for a genetic basis for susceptibility to ETEC-F4 since not all pigs suffer from diarrhoea after an ETEC-F4 infection. A region on SSC13 has been found to be in close linkage to the susceptibility of piglets for ETEC-F4ab,ac. Potential candidate genes on SSC13 have been examined and although some polymorphisms were found to be in linkage disequilibrium with the phenotype, the causative mutation has not yet been found. In this study we are looking at the expression of porcine genes in relation to ETEC-F4ab,ac. With the aid of the Affymetrix GeneChip Porcine Genome Array we were able to find differentially expressed genes between ETEC-F4ab,ac receptor positive (Fab,acR(+)) piglets without diarrhoea and F4ab,acR(+) piglets with diarrhoea or F4ab,acR(-) animals. Since the susceptibility to ETEC-F4ab,ac was described as a Mendelian trait, it is not so surprisingly that only two differentially expressed genes, transferrin receptor (TFRC) and trefoil factor 1 (TFF1), came out of the analysis. Although both genes could pass for functional candidate genes only TFRC also mapped to the region on SSC13 associated with susceptibility for ETEC-F4, which makes TFRC a positional functional candidate gene. Validation by qRT-PCR confirmed the differential expression of TFRC and TFF1. In piglets without diarrhoea, the expression of both genes was higher in F4ab,acR(+) than in F4ab,acR(-) piglets. Similarly, TFRC and TFF1 expression in F4ab,acR(+) piglets without diarrhoea was also higher than in F4ab,acR(+) piglets with diarrhoea. Consequently, although both genes might not play a role as receptor for F4 fimbriae, they could be of great importance during an ETEC-F4 outbreak. An upregulation of TFRC can be a consequence of the piglets ability to raise an effective immune response. An elevation of TFF1, a protein involved in mucin formation, may also affect the piglet's capability to cope with ETEC bacteria, rather than being a receptor for its fimbriae.

Ancestral haplotype-based association mapping with generalized linear mixed models accounting for stratification

MOTIVATION

In many situations, genome-wide association studies are performed in populations presenting stratification. Mixed models including a kinship matrix accounting for genetic relatedness among individuals have been shown to correct for population and/or family structure. Here we extend this methodology to generalized linear mixed models which properly model data under various distributions. In addition we perform association with ancestral haplotypes inferred using a hidden Markov model.

RESULTS

The method was shown to properly account for stratification under various simulated scenari presenting population and/or family structure. Use of ancestral haplotypes resulted in higher power than SNPs on simulated datasets. Application to real data demonstrates the usefulness of the developed model. Full analysis of a dataset with 4600 individuals and 500 000 SNPs was performed in 2 h 36 min and required 2.28 Gb of RAM.

AVAILABILITY

The software GLASCOW can be freely downloaded from www.giga.ulg.ac.be/jcms/prod_381171/software.

CONTACT

francois.guillaume@jouy.inra.fr

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Genetic variation in PLAG1 associates with early life body weight and peripubertal weight and growth in Bos taurus

Variation at the pleiomorphic adenoma gene 1 (PLAG1) locus has recently been implicated in the regulation of stature and weight in Bos taurus. Using a population of 942 outbred Holstein-Friesian dairy calves, we report confirmation of this effect, demonstrating strong association of early life body weight with PLAG1 genotype. Peripubertal body weight and growth rate were also significantly associated with PLAG1 genotype. Growth rate per kilogram of body weight, daily feed intake, gross feed efficiency and residual feed intake were not significantly associated with PLAG1 genotype. This study supports the status of PLAG1 as a key regulator of mammalian growth. Further, the data indicate the utility of PLAG1 polymorphisms for the selection of animals to achieve enhanced weight gain or conversely to aid the selection of animals with lower mature body weight and thus lower maintenance energy requirements.

Mutations in the myostatin gene leading to hypermuscularity in mammals: indications for a similar mechanism in fish?

The transforming growth factor β (TGF-β) superfamily encodes secreted factors that are important in regulating embryonic development and tissue homeostatis in adults. Myostatin (MSTN, encoded by MSTN) or 'growth and differentiation factor 8', a member of this superfamily, is a negative regulator of skeletal muscle growth and is highly conserved among animal species. In 1997, a mutation associated with the so-called double-muscling phenotype in cattle was found in the MSTN gene. During the years following the discovery of the first MSTN mutation, other mutations were found in cattle and other mammalian species, and MSTN became one of the most thoroughly studied genes in animals. The aim of this review is mainly to describe the functional mutations located in the MSTN genes of several mammalian species, leading to double muscling in these animals. Furthermore, in light of the increasing importance of fish genetics, the possibility of functional mutations in piscine MSTN with a similar effect as in mammals, and a genetic model for MSTN research in fish, will also be discussed.

Interactions between genes involved in growth and muscularity in pigs: IGF-2, myostatin, ryanodine receptor 1, and melanocortin-4 receptor

In the swine breeding industry, two economical traits are of particular importance in sires, namely, muscle growth and average daily gain (ADG). These traits are quantitative, which implies that they are under the control of multiple genes. Mutations in these genes, associated with either muscularity or growth, are useful quantitative trait nucleotides (QTN) for unraveling genetic variation of these traits and can be used in marker-assisted selection. Until now, QTN involved in muscle growth and/or ADG in pigs were identified in porcine ryanodine receptor 1 (RYR1), insulin-like growth factor-2 (IGF-2), and melanocortin-4 receptor (MC4R). Recently, a fourth possible QTN was found in porcine myostatin (MSTN). All four QTN have an influence on muscle growth and/or somatic growth, so an influence of one mutation on one or more of the other mutations should not be excluded. However, although the polymorphisms in the RYR1 and the MC4R gene affect the function of the respective protein, the polymorphisms of the IGF-2 and MSTN gene influence the mRNA expression of the respective gene. Therefore, this study investigated possible interactions between the genotypes of MSTN, IGF-2, and MC4R (population 1) or the RYR1, IGF-2, and MSTN QTN (population 2) on IGF-2 and MSTN expression in different muscle types in pigs. In both skeletal muscle and heart muscle growth, the IGF-2:MSTN ratio seems to play an important role. Also, the RYR1 genotype had a significant effect on IGF-2 expression in m. longissimus dorsi. No effect of the MC4R QTN could be seen.

Analysis of genetic variation in the Belgian Blue cattle breed using DNA sequence polymorphism at the growth hormone, low density lipoprotein receptor, alpha-subunit of glycoprotein hormones and thyroglobulin loci

New DNA sequence polymorphisms were identified at four bovine autosomal loci: growth hormone, low density lipoprotein receptor, alpha-subunit of glycoprotein hormones and thyroglobulin. Assuming independent assortment between these polymorphisms, the probabilities to be heterozygous at these four loci are 0.48, 0.36, 0.10 and 0.77 respectively, within the Belgian Blue Cattle breed (BBCB). Nucleotide diversity was estimated, showing that animals from the BBCB are heterozygous for 1/1450 nucleotides, a value significantly lower than the 1/500 value found in man. Moreover, we have estimated that the mutation rate at the cytosines of CG dinucleotides is about 10 times higher than that for other nucleotides.

Genetic linkage between the bovine plasma protease inhibitor 2 (Pi-2) and S blood group loci

A linkage relationship has been detected between the bovine plasma protease inhibitor 2 (Pi-2) and S blood group loci by linkage study within a single pedigree. Using the sequential lodscore test, the recombination fraction (theta) with maximum likelihood has been estimated at 0.200 +/- 0.043, with a maximum lodscore value of 3.466 at theta = 0.200.

The bovine gene map

The present status of the bovine gene map as well as some of the methods and strategies important for future efforts in completing the gene map of cattle are reviewed.

Genetic variation of the bovine thyroglobulin gene studied at the DNA level

The bovine thyroglobulin gene has been analysed for variation using restriction endonucleases. Six independent restriction fragment length polymorphisms have been identified. One of these results most probably from a 2.5-kb deletion, the others being compatible with point mutations. We determined that an individual taken at random within the Belgian White and Blue breed is, on average, heterozygous for one out of 1700 nucleotides within the thyroglobulin gene.