The cat has long been important to human societies as a pest-control agent, object of symbolic value and companion animal, but little is known about its domestication process and early anthropogenic dispersal. Here we show, using ancient DNA analysis of geographically and temporally widespread archaeological cat remains, that both the Near Eastern and Egyptian populations of Felis silvestris lybica contributed to the gene pool of the domestic cat at different historical times. While the cat's worldwide conquest began during the Neolithic period in the Near East, its dispersal gained momentum during the Classical period, when the Egyptian cat successfully spread throughout the Old World. The expansion patterns and ranges suggest dispersal along human maritime and terrestrial routes of trade and connectivity. A coat-colour variant was found at high frequency only after the Middle Ages, suggesting that directed breeding of cats occurred later than with most other domesticated animals.

Deciphering the plastic (non-heritable) changes induced by human control over wild animals in the archaeological record is challenging. We hypothesized that changes in locomotor behaviour in a wild ungulate due to mobility control could be quantified in the bone anatomy. To test this, we experimented with the effect of mobility reduction on the skeleton of wild boar ( Sus scrofa ), using the calcaneus shape as a possible phenotypic marker. We first assessed differences in shape variation and covariation in captive-reared and wild-caught wild boars, taking into account differences in sex, body mass, available space for movement and muscle force. This plastic signal was then contrasted with the phenotypic changes induced by selective breeding in domestic pigs. We found that mobility reduction induces a plastic response beyond the shape variation of wild boars in their natural habitat, associated with a reduction in the range of locomotor behaviours and muscle loads. This plastic signal of captivity in the calcaneus shape differs from the main changes induced by selective breeding for larger muscle and earlier development that impacted the pigs' calcaneus shape in a much greater extent than the mobility reduction during the domestication process of their wild ancestors.

Background: Failure in the regulation of homeostatic water balance in the brain is associated with severe cerebral edema and increased brain weights and may also play an important role in the pathogenesis of sudden infant death syndrome (SIDS). We genotyped three single-nucleotide polymorphisms in the aquaporin-4 water channel-encoding gene (AQP4), which were previously shown to be associated with (i) SIDS in Norwegian infants (rs2075575), (ii) severe brain edema (rs9951307), and (iii) increased brain water permeability (rs3906956). We also determined whether the brain/body weight ratio is increased in SIDS infants compared with sexand age-matched controls. Methods: Genotyping of the three AQP4 single-nucleotide polymorphisms was performed in 160 Caucasian SIDS infants and 181 healthy Swiss adults using a single-base extension method. Brain and body weights were measured during autopsy in 157 SIDS and 59 non-SIDS infants. results: No differences were detected in the allelic frequencies of the three AQP4 single-nucleotide polymorphisms between SIDS and adult controls. The brain/body weight ratio was similarly distributed in SIDS and non-SIDS infants. conclusion: Variations in the AQP4 gene seem of limited significance as predisposing factors in Caucasian SIDS infants. Increased brain weights may only become evident in conjunction with environmental or other genetic risk factors. s udden infant death syndrome (SIDS) is defined as the sudden and unexpected death of an infant younger than one year of age, which remains unexplained even after a complete investigation of the circumstances of death (1). According to the triple risk model proposed in 1994, the occurrence of SIDS involves three overlapping classes of SIDS-associated risk factors, namely (i) a vulnerable infant, (ii) a critical developmental period, and (iii) exogenous stress factors (2,3). While many of the exogenous stress factors, such as prone sleeping position, overheating, or maternal smoking during pregnancy, are well described, the genetic pathogenesis of SIDS remains poorly understood (4-8).Aquaporin-4 (AQP4) water channels are the main water transporters in the brain and are responsible for the active transport of water and small solutes across cell membranes at the blood-brain and brain-cerebrospinal fluid barriers (9). The highest density of AQP4 is expressed in astrocytic endfeet membranes and allows bidirectional transport of water to regulate the brain volume and ion homeostasis depending on the level of neuronal activity (10,11). Failure in the regulation of the homeostatic water balance can result in osmotic expansion of astrocytes, known as cytotoxic edema, which is typically accompanied by brain swelling (12). The involvement of AQP4 in the formation of brain edema was demonstrated in AQP4-deficient mice that experienced less astrocytic swelling and improved survival after acute water intoxication than wild-type mice (13). Water permeability assays further demonstrated that even partial knock-down variations in the AQP4 gene could reduc...

The origin and dispersal of the domestic cat remain elusive despite its importance to human societies around the world. Archaeological evidence for domestication centers in the Near East and in Egypt is contested, and genetic data on modern cats show that Felis silvestris lybica, the subspecies of wild cat inhabiting at present the Near East and Northern Africa, is the only ancestor of the domestic cat. Here we provide the first broad geographic and chronological dataset of ancient cat mtDNA sequences, drawing on archaeological specimens from across western Eurasia and northern and eastern Africa, dating from throughout the Holocene and spanning ~9,000 years. We characterized the ancient phylogeography of F. s. lybica, showing that it expanded up to southeastern Europe prior to the Neolithic, and reconstructed the subsequent movements that profoundly transformed its distribution and shaped its early cultural history. We found that maternal lineages from both the Near East and Egypt contributed to the gene pool of the domestic cat at different historical times, with the Near Eastern population providing the first major contribution during the Neolithic and the Egyptian cat spreading efficiently across the Old World during the Classical period. This expansion pattern and range suggest dispersal along maritime and terrestrial routes of trade and connectivity. Late trait selection is suggested by the first occurrence in our dataset of the major allele for blotched-tabby body marking not earlier than during the Late Middle Ages. SignificanceThe cat has long been important to human societies as a pest-control agent, object of symbolic value, and companion animal, but little is known about its domestication process and early anthropogenic dispersal. Our DNA analyses of geographically and temporally widespread archaeological cat remains show that while the cat's world-wide conquest began in prehistoric times, when tamed cats accompanied humans on their journeys over land and sea, it gained momentum during the Classical period, when the Egyptian cat successfully spread throughout the ancient world. The appearance of a new coat pattern at the end of the Middle Ages suggests late breeding control that might explain the semi-domestic status of the cat. This distinguishes the domestication process of cats from that of most other domesticates.All rights reserved. No reuse allowed without permission.(which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.

The sodium/proton exchanger protein 3 (NHE3) is located in chemosensitive areas of the medulla oblongata and plays an important role in the central control of respiration. Overexpression of NHE3 is correlated with lower respiration and might therefore contribute to the vulnerability of infants dying suddenly and unexpected (sudden infant death syndrome, SIDS). Our aim in this study was to verify already reported genetic variations in the NHE3 gene in an independent SIDS cohort from Switzerland. Two single nucleotide polymorphisms (SNPs) in the promoter region (G1131A and C1197T) and one variation in the coding sequence of exon 16 (C2405T) in the NHE3 gene were analyzed in 160 Caucasian SIDS infants and 192 Swiss adult controls by using a single base extension method (SNaPshot multiplex). No significant differences were detected in the allelic frequencies of the three NHE3 polymorphisms between SIDS cases and controls. We conclude that the three investigated NHE3 SNPs are unlikely to play a major role in the pathogenesis of SIDS in Caucasian infants. However, further genetic investigations in different ethnicities are required to determine whether variations in NHE3 are associated with an increased SIDS risk.