Tracing the Inside of Pigs Non-Invasively: Recent Developments

Regional markets require a large variety of pig breeds and pork products. Noninvasive techniques like computed tomography, magnetic resonance imaging, dual-energy X-ray absorptiometry, computer vision, or, very often, ultrasound helps to provide the information required for breeding, quality control, payment, and processing. Meanwhile, computed tomography is being used as phenotyping tool by leading pig breeding organizations around the world, while ultrasound B- or A-mode techniques belong to the standard tools, especially to measure subcutaneous fat and muscle traits. Magnetic resonance imaging and dual-energy X-ray absorptiometry, however, are still mainly used as research tools to develop and characterize new phenotypic traits, which usually could not be measured without slaughtering the breeding pigs. A further noninvasive method—already used on a commercial basis, not only in abattoirs—is video 2D or 3D imaging. This chapter will review the latest developments for these noninvasive techniques

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Disease: A Hitherto Unexplored Constraint on the Spread of Dogs (Canis lupus familiaris) in Pre-Columbian South America

Although debate continues, there is agreement that dogs (Canis lupus familiaris) were first domesticated in Eurasia, spreading from there to other parts of the world. However, while that expansion already extended as far as Europe, China, and North America by the early Holocene, dogs spread into (and south of) the tropics only much later. In South America, for example, the earliest well attested instances of their presence do not reach back much beyond 3000 cal. BC, and dogs were still absent from large parts of the continent – Amazonia, the Gran Chaco, and much of the Southern Cone – at European contact. Previous explanations for these patterns have focused on cultural choice, the unsuitability of dogs for hunting certain kinds of tropical forest prey, and otherwise unspecified environmental hazards, while acknowledging that Neotropical lowland forests witness high rates of canine mortality. Building on previous work in Sub-Saharan Africa (Mitchell 2015) and noting that the dog’s closest relatives, the grey wolf (C. lupus) and the coyote (C. latrans), were likewise absent from South and most of Central America in Pre- Columbian times, this paper explores instead the possibility that infectious disease constrained the spread of dogs into Neotropical environments. Four diseases are considered, all likely to be native and/or endemic to South America: canine distemper, canine trypanosomiasis, canine rangeliosis, and canine visceral leishmaniasis caused by infection with Leishmania amazonensis and L. colombiensis. The paper concludes by suggesting ways in which the hypothesis that disease constrained the expansion of dogs into South America can be developed further

Effects of dietary conjugated linoleic acid on growth and body composition of control and IGF-I transgenic pigs

Both dietary conjugated linoleic acid (CLA) and presence of the IGF-I transgene are reported to alter the fat:lean content of pigs. The purpose of this study was to compare the growth and body composition of control and IGF-I transgenic pigs in response to dietary CLA. Transgenic (TG) pigs expressing the IGF-I gene and sibling control (C) progeny were produced by mating two half-sib G-1 transgenic boars to non-transgenic gilts. At 60 kg each pig was scanned by dual-energy X-ray absorptiometry (DXA) for body composition analysis, then placed on an 18% crude protein diet containing either 2% corn oil (CO diet) or 1.2% CO plus 0.8% CLA. Thus, the four genotype-diet combinations were: C-CO (n=25), C-CLA (n=25), TG-CO (n=24), and TG-CLA (n=23). Each pig was scanned again at 110 kg. All pigs were slaughtered at 120 kg and the right half-carcass was scanned by DXA. Results of the DXA scan at 60 kg revealed that the TG pigs were less fat (15.0%) than the C pigs (18.8%, P < 0.05). During growth from 60 to 110 kg, the tissue gain for the C-CO, C-CLA, TG-CO, and TG-CLA groups consisted of 16.6, 14.5, 13.2, and 13.0 kg of fat (P < 0.05, C-CO vs. C-CLA and C vs. TG); and 30.6, 32.6, 33.7, and 33.8 kg of lean (P < 0.05, C-CO vs. C-CLA and C vs. TG), respectively. There were only minor differences in bone growth. For the same groups, chemical analysis of the half-carcass revealed 29.2, 27.1, 23.8, and 22.8% fat (P < 0.05 for C-CO vs. C-CLA and C vs. TG), respectively. Overall, the effects of CLA were less than those of TG on body or carcass composition; however, during the treatment period from 60 to 110 kg, the effects were similar. TG pigs did not respond to CLA as much as did control pigs.Effets de l’acide linoléique conjugué sur la croissance et la composition corporelle de porcs normaux et transgéniques IGF-I. L’acide linoléique conjugué (CLA) et la présence du transgène IGF-I ont tous deux des effets sur la composition corporelle du porc. L’objectif de cette étude était de comparer la croissance et la composition corporelle de porcs normaux et transgéniques IGF-I recevant dans leur ration du CLA. Des porcs transgéniques exprimant le gène IGF-I (TG) et des porcs témoins (C) ont été produits en croisant 2 verrats transgéniques de la même famille avec des truies normales. A 60 kg, chaque porc a été scanné par absorptiométrie biphotonique à rayons X (dual-energy X-ray absorptiometry, DXA) et a reçu une ration avec 18 % de matières azotées, contenant soit 2,0 % d’huile de maïs (CO), soit 1,2 % d’huile de maïs et 0,8 % de CLA. Ainsi 4 combinaisons génotypes × rations ont été obtenues : C-CO (n=25), C-CLA (n=25), TG-CO (n=24) et TG-CLA (n=23). Chaque porc a été de nouveau scanné à 110 kg. Tous ont été abattus à 120 kg et leur demi-carcasse droite scannée et analysée chimiquement. Les résultats de la scanographie faite à 60 kg montrent que les porcs TG avaient une teneur moindre en gras (15,0 %) que les porcs C (18,8 %, P < 0,05). Durant la période de croissance de 60 à 110 kg, le gain tissulaire des groupes C-CO, C-CLA, TG-CO et TG-CLA se composait de 16,6, 14,5, 13,2 et 13,0 kg de gras (P < 0,05, C-CO vs. C-CLA et C vs. TG) et 30,6, 32,6, 33,7 et 33,8 kg de viande maigre (P < 0,05, C-CO vs. C-CLA et C vs. TG), respectivement. La croissance osseuse n’a montré que de faibles variations. Pour les mêmes groupes, la teneur en gras de la demi-carcasse, mesurée par analyse chimique, était de 29,2, 27,1, 23,8 et 22,8 % (P < 0,05, C-CO vs. C-CLA et C vs. TG) respectivement. D’une manière générale, les effets du CLA ont été moins prononcés sur la composition corporelle et sur la carcasse que ceux dus à la présence du transgène IGF-I, mais ils ont été semblables durant la période expérimentale de 60 à 110 kg. Les porcs TG ont été moins sensibles à l’apport de CLA que les porcs témoins