Genotyping KIF1C (c.608G>A) Mutant Reveals a Wide Distribution of Progressive Ataxia in German Charolais Cattle.

Bovine progressive ataxia in Charolais cattle was first described in the 1970s; then, cases were reported in Charolais worldwide. A homozygous loss-of-function mutation within the KIF1C gene (c.608G>A) was found to be responsible for this neurodegenerative disease. The aim of this study was to determine whether the mutated KIF1C allele segregates in the German Charolais population and whether the estimated breeding values for growth and muscle conformation are associated with the mutated genotypes. Genetic test results of the KIF1C:c.608G>A variant were available for 1315 Charolais cattle from 35 herds located in Germany. In addition, 324 samples from eight other beef cattle breeds were tested for the mutated KIF1C allele. We were able to demonstrate that the KIF1C mutation is common, with a frequency of 11.75% in the German Charolais population. All but two of the eight (2/8 = 25%) homozygous mutated individuals showed clinical signs consistent with progressive ataxia. The estimated breeding values of muscle conformation in 200- and 365-day-old animals indicated a significant superiority for homozygous mutated animals when compared either with heterozygous or homozygous wild-type genotypes; this was also the case for heterozygous genotypes in comparison with homozygous wild-type genotypes. For the estimated breeding values of daily weight gain in 200- and 365-day-old animals, the significant differences between homozygous mutated and heterozygous or wild-type genotypes were in favour of the homozygous mutant animals. There were no differences in the estimated maternal breeding values among all three KIF1C genotypes. For the first time, two German Angus cattle carrying the KIF1C mutation heterozygous were detected. The breeders' survey highlighted that increased awareness would facilitate increased conviction among breeders of the need for genetic testing in order to eliminate the lethal KIF1C allele.

A Missense Mutation in the Collagen Triple Helix of EDA Is Associated with X-Linked Recessive Hypohidrotic Ectodermal Dysplasia in Fleckvieh Cattle.

Mutations within the ectodysplasin A (EDA) gene have been associated with congenital hypotrichosis and anodontia (HAD/XHED) in humans, mice, dogs and cattle. We identified a three-generation family of Fleckvieh cattle with male calves exhibiting clinical and histopathological signs consistent with an X-linked recessive HAD (XHED). Whole genome and Sanger sequencing of cDNA showed a perfect association of the missense mutation g.85716041G>A (ss2019497443, rs1114816375) within the EDA gene with all three cases following an X-linked recessive inheritance, but normal EDAR and EDARADD. This mutation causes an exchange of glycine (G) with arginine (R) at amino acid position 227 (p.227G>R) in the second collagen triple helix repeat domain of EDA. The EDA variant was associated with a significant reduction and underdevelopment of hair follicles along with a reduced outgrowth of hairs, a complete loss of seromucous nasolabial and mucous tracheal and bronchial glands and a malformation of and reduction in number of teeth. Thermostability of EDA G227R was reduced, consistent with a relatively mild hair and tooth phenotype. However, incisors and canines were more severely affected in one of the calves, which correlated with the presence of a homozygous missense mutation of RNF111 (g.51306765T>G), a putative candidate gene possibly associated with tooth number in EDA-deficient Fleckvieh calves.

AA-amyloidosis in captive northern tree shrews (Tupaia belangeri).

A high prevalence of AA-amyloidosis was identified in a breeding colony of northern tree shrews (Tupaia belangeri) in a retrospective analysis, with amyloid deposits in different organs being found in 26/36 individuals (72%). Amyloid deposits, confirmed by Congo red staining, were detected in kidneys, intestines, skin, and lymph nodes, characteristic of systemic amyloidosis. Immunohistochemically, the deposited amyloid was intensely positive with anti-AA-antibody (clone mc4), suggesting AA-amyloidosis. The kidneys were predominantly affected (80%), where amyloid deposits ranged from mild to severe and was predominantly located in the renal medulla. In addition, many kidneys contained numerous cysts with atrophy of the renal parenchyma. There was no significant association between concurrent neoplastic or inflammatory processes and amyloidosis. The lack of distinctive predisposing factors suggests a general susceptibility of captive T. belangeri to develop amyloidosis. Clinical and laboratory findings of a female individual with pronounced kidney alterations were indicative of renal failure. The observed tissue tropism with pronounced kidney alterations, corresponding renal dysfunction, and an overall high prevalence suggests amyloidosis as an important disease in captive tree shrews.

Clinical, cytogenetic and molecular genetic characterization of a tandem fusion translocation in a male Holstein cattle with congenital hypospadias and a ventricular septal defect.

Hypospadias, disorder of sex development (DSD), is a sporadic congenital abnormality of the genital region in male ruminants, which is characterized by a non-fused urethra during fetal development. Detailed clinical examination classified the hypospadias phenotype of a male Holstein calf studied here as the perineal type. In combined use of cytogenetic analysis and whole genome sequencing, a non-mosaic, pseudo-monosomy 59, XY + tan(18;27) was detected. This chromosomal aberration had its origin in a tandem fusion translocation of the bovine autosomes (BTA) 18 and 27 with an accompanying loss of genomic sequences mainly in the distal end of BTA 18 and the proximal end of BTA 27. The resulting phenotype included hypospadias, growth retardation and ventricular septal defect.

Study of congenital Morgagnian cataracts in Holstein calves.

Cataracts are focal to diffuse opacities of the eye lens causing impaired vision or complete blindness. For bilateral congenital cataracts in Red Holsteins a perfectly cosegregating mutation within the CPAMD8 gene (CPAMD8:g.5995966C>T) has been reported. We genotyped the CPAMD8:g.5995966C>T variant in Holstein calves affected by congenital bilateral congenital cataracts, their unaffected relatives and randomly selected herd mates. Ophthalmological examinations were performed in all affected individuals to confirm a congenital cataract. Whole genome sequencing was employed to screen variants in candidate genes for the Morgagnian cataract phenotype. In the present study, 3/35 cases were confirmed as homozygous mutated and 6/14 obligate carriers. Further 7/46 unaffected animals related with these cases were heterozygous mutated for the CPAMD8:g.5995966C>T variant. However 32 cases with a congenital cataract showed the wild type for the CPAMD8 variant. We did not identify variants in the candidate genes CPAMD8 and NID1 or in their close neighborhood as strongly associated with the congenital cataract phenotype in Holstein calves with the CPAMD8 wild type. In conclusion, the CPAMD8:g.5995966C>T variant is insufficient to explain the majority of Morgagnian congenital cataract phenotypes in Holsteins. It is very likely that congenital bilateral cataracts may be genetically heterogeneous and not yet known variants in genes other than CPAMD8 and NID1 are involved.

Split spinal cord malformations in 4 Holstein Friesian calves.

BACKGROUND: The split spinal cord malformation (SSCM) is an uncommon congenital malformation of the vertebral canal in which parts of the spinal cord are longitudinally duplicated. In SSCM Type I, each spinal cord has its own dura tube. In the SSCM Type II, both parts of the spinal cord are surrounded by a common dura tube. CASES PRESENTATION: During the clinical examination one calf showed ambulatory paresis and 3 calves non-ambulatory paraparesis. Calf 4 additionally had a congenital tremor. The examination of calf 4 using magnetic resonance imaging (MRI) showed a median hydrosyringomyelia at the level of the 4th lumbar vertebra. The caudal part of this liquid-filled cavity was split longitudinally through a thin septum. From there, the spinal cord structures duplicated with an incomplete division, so that the transverse section of the spinal cord appeared peanut-shaped and in each half a central canal could be observed. The pathological-anatomical examination after euthanasia showed a duplication of the spinal cord in the area of the lumbar vertebral column in all calves. The histopathological examination revealed two central lumbar vertebral column channels. The two spinal cord duplicates were each surrounded by two separate meninges in calf 2 (SSCM type I); in the other calves (1, 3, 4, and) the two central canals and the spinal cord were covered by a common meninx (SSCM type II). A pedigree analysis of calves 2, 3 and 4 showed a degree of relationship suggestive of a hereditary component. This supports the hypothesis of a possible recessive inheritance due to common ancestors, leading to partial genetic homozygosity. CONCLUSIONS: The clinical appearance of SSCM can vary widely. In calves with congenital paralysis SSCM should always be considered as a differential diagnosis. A reliable diagnosis intra vitam is possible only with laborious imaging procedures such as MRI. Further studies on the heritability of this malformation are necessary to confirm a genetic cause of this disease.

Germline mutation within COL2A1 associated with lethal chondrodysplasia in a polled Holstein family.

BACKGROUND: The bulldog calf syndrome is a lethal form of the inherited congenital chondrodysplasias. Among the progeny of the polled Holstein bull Energy P cases of lethal chondrodysplasia were observed. Pedigrees of the cases and the frequency of 3/8 cases among the offspring of Energy P at our teaching and experimental farm Ruthe (LuFG Ruthe) supported the assumption of a germline mutation with a mosaic of normal and defective sperm. RESULTS: All three malformed calves were examined using necropsy, histopathology and computed tomography scanning. The phenotypic appearance of the affected calves was highly similar; they presented with severe disproportionate dwarfism and reduced body weight. The syndrome was characterized by brachygnathia superior, bilateral palatoschisis, shortening and compression of the body due to malformed vertebrae, in their size reduced and malformed ribs and reduced length of the long bones of the limbs. The bones had small irregular diaphyses and enlarged epiphyses. Whole genome sequencing of one bulldog calf, sperm of its sire Energy P and a normal progeny of Energy P identified a deleterious missense mutation (g.32476082G > A, c.2986G > A, ss2019324576) within COL2A1 on bovine chromosome (BTA) 5. Sanger sequencing confirmed the ss2019324576 variant in the affected calves and sperm of Energy P. This mutation is located within the collagen triple helix repeat and causes an exchange of glycine to serine (p.996G > S) in COL2A1. This private single nucleotide variant (SNV) was present as a gonadal mosaic in sperm of the bull. All affected calves were in a heterozygous state whereas normal half-siblings and all dams of the progeny from Energy P were missing this SNV. Validation in polled Holstein bulls and normal Holstein calves randomly sampled from several herds and from the LuFG Ruthe confirmed this SNV as private. CONCLUSIONS: The identified spontaneous missense mutation within COL2A1 is most likely the cause of lethal chondrodysplasia in the progeny of Energy P through a dominant negative effect. This example suggests that it would be beneficial to conduct whole genome sequencing of sperm from bulls widely used in artificial insemination in order to detect germline mosaicism.

Validation of Deleterious Mutations in Vorderwald Cattle.

In Montbéliarde cattle two candidate mutations on bovine chromosomes 19 and 29 responsible for embryonic lethality have been detected. Montbéliarde bulls have been introduced into Vorderwald cattle to improve milk and fattening performance. Due to the small population size of Vorderwald cattle and the wide use of a few Montbéliarde bulls through artificial insemination, inbreeding on Montbéliarde bulls in later generations was increasing. Therefore, we genotyped an aborted fetus which was inbred on Montbéliarde as well as Vorderwald x Montbéliarde crossbred bulls for both deleterious mutations. The abortion was observed in an experimental herd of Vorderwald cattle. The objectives of the present study were to prove if one or both lethal mutations may be assumed to have caused this abortion and to show whether these deleterious mutations have been introduced into the Vorderwald cattle population through Montbéliarde bulls. The aborted fetus was homozygous for the SLC37A2:g.28879810C>T mutation (ss2019324563) on BTA29 and both parents as well as the paternal and maternal grandsire were heterozygous for this mutation. In addition, the parents and the paternal grandsire were carriers of the MH2-haplotype linked with the T-allele of the SLC37A2:g.28879810C>T mutation. For the SHBG:g.27956790C>T mutation (rs38377500) on BTA19 (MH1), the aborted fetus and its sire were heterozygous. Among all further 341 Vorderwald cattle genotyped we found 27 SLC37A2:g.28879810C>T heterozygous animals resulting in an allele frequency of 0.0396. Among the 120 male Vorderwald cattle, there were 12 heterozygous with an allele frequency of 0.05. The SLC37A2:g.28879810C>T mutation could not be found in further nine cattle breeds nor in Vorderwald cattle with contributions from Ayrshire bulls. In 69 Vorderwald cattle without genes from Montbéliarde bulls the mutated allele of SLC37A2:g.28879810C>T could not be detected. The SHBG:g.27956790C>T mutation appeared unlikely to be responsible for the present case of abortion and, in addition, we observed this mutation in a homozygous state in a living animal. In conclusion, we could demonstrate the first case of an aborted fetus carrying the deleterious SLC37A2:g.28879810C>T mutation homozygous and show that this deleterious mutation had been introduced through Montbéliarde bulls into Vorderwald cattle.

[Congenital and lethal semi-hairlessness in an Angler-Holstein crossbred calf]. / Kongenitale und letale Semi-Haarlosigkeit bei einem Angler-Holstein Kreuzungskalb.

A male Angler-Red Holstein crossbred calf was almost completely hairless since its birth. Hair growth was not observed within the course of its life, but with increasing age the hair structure changed from a thin and soft hair to a wiry to coarse hair fibre. Growth rate of the animal was reduced, body condition was poor but appetite was good. In addition, accompanying malformations were found including brachygnathia superior and a reduction or a particularly pronounced fine countenance skull ("shrew head"). The calf died unexpectedly at the age of five months. In the subsequent gross pathological and histopathological examination, a pronounced hyperkeratosis, degeneration of follicular epithelial cells, a reduced number of hair follicles, an increased number of telogen hair follicles, sclerosis of the corium, dilated apocrine glands and inflammatory changes of the gastrointestinal tract were seen. Based on the course of the disease, the phenotypic appearance of hypotrichosis and hair fibre as well as the histopathological changes the present case resembles a lethal semi-hairless form of hypotrichosis. This congenital anomaly in the present case is likely genetically determined.

[An unusual case of a 35 days preterm birth of a German Holstein calf]. / Ein außergewöhnlicher Fall eines 35 Tage zu früh geborenen Deutschen Holstein Kalbes.

A female calf of the breed German Holstein (GH) was spontaneously born on July 28, 2013 which was 35 days before the expected term of birth. The dam was a heifer when she got pregnant from the first insemination on November 23, 2012. Calving was without complications. The calf was fully viable and without visible anomalies. We assume that the calf was fully mature at the termination of the pregnancy. Growth rate after the second month of life was comparable to calves born in the same herd after normal length of gestation. The sire of this preterm calf was a GH-bull used for artificial insemination. This bull had already sired 151 daughters. For this bull, preterm calvings were not yet reported. The dam was a heifer, and neither external influences on this dam or in the herd could be identified that could have induced this premature calving. In the herd, no further premature calvings were observed or reasons associated with a preterm calving were found. In this exceptional case, however, gestation length was 248 days and the prematurely born calf survived without any signs of debility, organ defects and respiratory distress.

Phenotypic classification of variability of non-syndromic congenital cleft lip and jaw in Vorderwald × Montbéliarde cattle.

BACKGROUND: Non-syndromic congenital cleft lip and jaw (CLJ) is a condition reported in several cattle breeds, but a detailed classification system does not exist for cattle. The objective of the present study was to describe the phenotypic variability of this orofacial malformation in Vorderwald × Montbéliarde cattle. For this purpose, a classification system of CLJ was developed on examination of five orofacial structures: (1) lips, (2) the processus (proc.) nasalis of the os incisivum, (3) the dental plate with adjacent segments of the hard palate, (4) the facial bones (os incisivum, os maxillare, os nasale and os palatinum) and (5) the mandibles. Each structure was given a score reflecting the degree of the lesion from absent (score 0) to severe. RESULTS: Nine cases were included in the study and they shared absence of the abaxial rostral part of the processus (proc.) nasalis of the os incisivum, partial loss of the rugae palatinae and the dental plate. A sigmoid curvature of the rostral lower jaw as well as a lateral deviation of the face and rostral lower jaw was highly variable in their expression. These deformations were present in eight of nine cases. In addition to the complete CLJ, three animals had an incomplete CLJ on the contralateral site with variable defects of the rostral part of the proc. nasalis of the os incisivum. CONCLUSIONS: A complete CLJ is obviously accompanied by a loss of parts of the proc. nasalis of the os incisivum. Extent and localization of the missing parts of the proc. nasalis were similar in all cases. A precise classification of the various CLJ forms is necessary.