A testudinid herpesvirus 1 (TeHV1)-associated disease outbreak in a group of Horsfield's tortoises (Testudo horsfieldii).

In spring 2020, a severe disease outbreak with high morbidity and mortality was observed in a collection of 15 Horsfield's tortoises (Testudo horsfieldii). Affected tortoises showed upper respiratory- and gastrointestinal tract signs, including rhinitis and stomatitis. Testudinid herpesvirus 1 (TeHV1) and Mycoplasma spp. were detected by PCR in oral swabs of affected animals. Histological examination of one deceased animal showed intranuclear inclusion bodies typical for herpesvirus infections in liver, spleen and oesophagus. The virus was likely introduced into the collection 2 years earlier by a clinically healthy Horsfield's tortoise that was tested positive for TeHV1 by PCR.

DETECTION OF OPHIDIOMYCES OPHIODIICOLA IN TWO CAPTIVE BOCOURT WATER SNAKES ( SUBSESSOR BOCOURTI) AND ONE CAPTIVE PUEBLAN MILK SNAKE ( LAMPROPELTIS TRIANGULUM CAMPBELLI).

Two captive Bocourt water snakes ( Subsessor bocourti) presented with chronic white skin lesions on their heads; Ophidiomyces ophiodiicola was identified by culture and polymerase chain reaction (PCR) in skin scrapings from both snakes. Histopathology performed in one Bocourt water snake revealed fungal hyphae in epidermal structures of lesions. One Pueblan milk snake ( Lampropeltis triangulum campbelli) from the same zoologic institution presented with yellow crusts and white blisters on its body, from which O. ophiodiicola was identified by culture and PCR. Two of the three snakes apparently recovered from lesions after multiple natural sheds, whereas the third snake died. This is the first report of O. ophiodiicola infection in Bocourt water snakes and in a Pueblan milk snake, as well as the first report of O. ophiodiicola in France.

Physics of amniote formation.

We present a detailed study of the formation of the amniotic sac in the avian embryo, and a comparison with the crocodile amniotic sac. We show that the amniotic sac forms at a circular line of stiffness contrast, separating rings of cell domains. Cells align at this boundary, and this in turn orients and concentrates the tension forces. The tissue fold which forms the amniotic sac is locked exactly along this line due to the colocalization of the stiffness contrast and of the tensile force. In addition, the tensile force plays a regenerative role when the amniotic sac is cut. The fold forming the ventral side of the embryo displays the same characteristics. This work shows that amniote embryogenesis consists of a cascade of buckling events taking place at the boundaries between regions of differing mechanical properties. Hence, amniote embryogenesis relies on a simple and robust biomechanical scheme used repeatedly, and selected ancestrally.