Antenatal anticipation of postnatal muscle function.
The semitendinosus muscle of the sheep was used as an experimental model to test antenatal anticipation of muscle postnatal function using the alkali-stabile myosin ATPase technique. Areas of variable fibre type population density were seen from 80 days of gestation. The highest population density of ATPase-low fibres was observed in the craniomedial aspect of the muscle (the ATPase-low dense area). The lowest ATPase-low fibre population density area (the ATPase-low sparse area) was seen in the caudolateral aspect of the muscle. Simultaneous electromyographic studies indicated that the ATPase-low dense area is preferentially used for posture and during quiet co-ordinated activity, while the ATPase-low sparse area is recruited only intermittently when the hip and stifle are less co-ordinated in movement. The ATPase-low fibre percentage within the ATPase-low dense area of the muscle increased from 10 to 30% from 80 days of gestation to adulthood. The part of this change occurring antenatally is expected to be the result of genetic anticipation.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D004576:Electromyography; D005260:Female; D005865:Gestational Age; D006651:Histocytochemistry; D008297:Male; D009132:Muscles / Q000196:embryology* / Q000201:enzymology / Q000502:physiology; D012756:Sheep; D013848:Thigh
D000251:Adenosine Triphosphatases