Facial asymmetry tracks genetic diversity among Gorilla subspecies.

Mountain gorillas are particularly inbred compared to other gorillas and even the most inbred human populations. As mountain gorilla skeletal material accumulated during the 1970s, researchers noted their pronounced facial asymmetry and hypothesized that it reflects a population-wide chewing side preference. However, asymmetry has also been linked to environmental and genetic stress in experimental models. Here, we examine facial asymmetry in 114 crania from three Gorilla subspecies using 3D geometric morphometrics. We measure fluctuating asymmetry (FA), defined as random deviations from perfect symmetry, and population-specific patterns of directional asymmetry (DA). Mountain gorillas, with a current population size of about 1000 individuals, have the highest degree of facial FA (explaining 17% of total facial shape variation), followed by Grauer gorillas (9%) and western lowland gorillas (6%), despite the latter experiencing the greatest ecological and dietary variability. DA, while significant in all three taxa, explains relatively less shape variation than FA does. Facial asymmetry correlates neither with tooth wear asymmetry nor increases with age in a mountain gorilla subsample, undermining the hypothesis that facial asymmetry is driven by chewing side preference. An examination of temporal trends shows that stress-induced developmental instability has increased over the last 100 years in these endangered apes.

A homozygous missense variant in laminin subunit beta 1 as candidate causal mutation of hemifacial microsomia in Romagnola cattle.

Hemifacial microsomia (HFM) was diagnosed in a 9-day-old Romagnola calf. The condition was characterized by microtia of the left ear, anotia of the right ear, asymmetry of the face, and deafness. Magnetic resonance imaging revealed agenesis of the right pinna and both tympanic bullae, asymmetry of the temporal bones and temporomandibular joints, and right pontine meningocele. Brainstem auditory evoked responses confirmed the impaired auditory capacity. At gross post mortem examination, there was agenesis and hypoplasia of the right and the left external ear, respectively. No histological abnormalities were detected in the inner ears. A trio whole-genome sequencing approach was carried out and identified a private homozygous missense variant in LAMB1 affecting a conserved residue (p.Arg668Cys). Genotyping of 221 Romagnola bulls revealed a carrier prevalence <2%. This represents a report of a LAMB1-related autosomal recessive inherited disorder in domestic animals and adds LAMB1 to the candidate genes for HFM.

Pythiosis in cats in northeastern Brazil.

The epidemiological, clinical and anatomopathological aspects of pythiosis in cats in northeastern Brazil are described. From January 2000 to December 2018 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1928 tissue samples of cats, three of which were diagnosed as pythiosis. Grossly, the cats showed a multinodular mass in the oral cavity associated with facial deformity (case 1), a large multinodular mass thickening the jejunum wall (case 2), and an ulcerated nodule in the skin at the base of the tail (case 3). Histologically, pyogranulomatous inflammation and necrosis, with intralesional predominantly negatively stained hyphae, were observed in all cases. Immunohistochemistry for Pythium insidiosum revealed strong immunolabelling of the hyphae. The diagnosis of pythiosis was based on the epidemiological, clinical and anatomopathological findings, and was confirmed by immunohistochemistry. Although uncommon in cats, pythiosis should be readily considered as a differential diagnosis of chronic pyogranulomatous infections of the gastrointestinal tract and skin, especially in endemic areas, where the disease is often diagnosed in other animal species.

A Retrospective Study of Horner Syndrome in Australian Wild Birds, 2010-2016.

Horner syndrome was identified in 25 of 30 777 avian admissions to Currumbin Wildlife Hospital during 2010-2016. Unilateral ptosis and erection of facial feathers were distinct findings on physical examination and consistent across 9 species. Affected birds were biased toward adults (64%) suffering traumatic injuries (88%). Concurrent injuries requiring treatment were present in 38% of cases, and 76% had additional neurologic deficits. Prognosis for release was poor, with an overall success rate of 32%. Resolution of clinical signs increased to 44% with higher doses of meloxicam and required an average hospitalization of 22 days (range, 3-78 days). Further investigation of the underlying causes of Horner syndrome in birds to provide treatment and prognostic guidelines is warranted.

Type III hemifacial microsomia in a kitten.

The case described herein presented with craniofacial malformations resembling hemifacial microsomia (HFM), a congenital disorder described in humans. To our knowledge, this is the first reported case of HFM in a domestic cat.

Human assessment of chimpanzee facial asymmetry.

In this study, facial asymmetry in chimpanzees was assessed using a technique that has traditionally been implemented in human studies. Image composites made of each half of chimpanzees' facial expressions were presented to humans with and without chimpanzee experience. The group of subjects with chimpanzee experience considered composites made of the left side of the chimpanzee faces as the most emotionally intense for the emotional categories of play, silent bared-teeth, scream face, and a neutral category. On the other hand, left-left composites were not consistently judged by subjects with and without chimpanzee experience as the most similar to the whole original face, which might be explained as the result of an attentional bias in the human observers towards the right side of the chimpanzee expressions. Furthermore, responses given by subjects with and without chimpanzee experience were highly correlated, which indicates that the two groups of humans perceived the chimpanzee facial expressions in a similar fashion. The finding of left-sided asymmetries in these chimpanzees' facial expressions suggests a right hemisphere asymmetry in the production of emotions in this species and it is consistent with results reported in human and other nonhuman primates.

Unilateral hypoplasia of the palate and associated structures in a white-handed gibbon (Hylobates lar).

A hole in the palate was detected in a ten-day-old white-handed gibbon (Hylobates lar). The clinical observations demonstrated a unilateral hypoplasia of the palate, of the maxilla, of a tooth, and of the adjacent facial musculature and skin.