Batchelder C A, Whitcomb M B, Famula T R, Rodriguez-Villamil P, Bertolini M, Hoffert-Goeres K A, Anderson G B
Department of Animal Science, University of California, Davis, USA.
School of Veterinary Medicine, University of California, Davis, USA.
Theriogenology. 2017 Nov;103:153-161. doi: 10.1016/j.theriogenology.2017.07.023. Epub 2017 Jul 27.
The aim of this study was to compare cardiac morphology in newborn and month-old control and cloned calves. A total of 10 in vivo-derived (IVD) control (five Holstein, five Hereford) and seven cloned (five Holstein, two Hereford) calves were subjected to echocardiographic examination, including 2D, M-mode, spectral and color flow Doppler evaluation at Day 1 (mean 26.3 h) and Day 30 (mean 29.2 days) after birth. Echocardiographic measurements were compared between control and cloned calves, and between Hereford and Holstein control calves of the same age. At Day 1 and at Day 30 after birth, left ventricular free wall (LVFW) and interventricular septal (IVS) thicknesses were greater in Holstein calves than Hereford calves. Several indices of myocardial wall thickness were increased in cloned versus control calves at Day 1 after birth, and included systolic LVFW thickness, systolic right ventricular free wall (RVFW) thickness, diastolic LVFW thickness, diastolic RVFW thickness and diastolic IVS thickness (p < 0.05). Differences between cloned and non-cloned calves were no longer evident at Day 30 after birth. The apparent disappearance of the cloning effect on cardiac structures may reflect the influence of placenta on fetal cardiac morphology, suggestive of a placental hemodynamic role in fetal cardiac muscle development. Differences seen in clones at birth spontaneously resolved by Day 30 of age, after organ development recovery from cardiovascular abnormalities of presumed placental origin. Echocardiographic measurements should provide useful data for research and clinical evaluation of high-risk neonatal calves of both breeds and from clones of the same breed.
本研究的目的是比较新生及满月龄对照犊牛和克隆犊牛的心脏形态。总共10头体内衍生（IVD）对照犊牛（5头荷斯坦牛、5头赫里福德牛）和7头克隆犊牛（5头荷斯坦牛、2头赫里福德牛）接受了超声心动图检查，包括在出生后第1天（平均26.3小时）和第30天（平均29.2天）进行二维、M型、频谱和彩色多普勒血流评估。对对照犊牛和克隆犊牛之间，以及相同年龄的赫里福德对照犊牛和荷斯坦对照犊牛之间的超声心动图测量结果进行了比较。在出生后第1天和第30天，荷斯坦犊牛的左心室游离壁（LVFW）和室间隔（IVS）厚度大于赫里福德犊牛。出生后第1天，克隆犊牛与对照犊牛相比，心肌壁厚度的几个指标有所增加，包括收缩期LVFW厚度、收缩期右心室游离壁（RVFW）厚度、舒张期LVFW厚度、舒张期RVFW厚度和舒张期IVS厚度（p<0.05）。出生后第30天，克隆犊牛与非克隆犊牛之间的差异不再明显。克隆对心脏结构的影响明显消失，这可能反映了胎盘对胎儿心脏形态的影响，提示胎盘在胎儿心肌发育中具有血流动力学作用。出生时克隆犊牛中观察到的差异在30日龄时自发消失，此前器官发育已从假定源于胎盘的心血管异常中恢复。超声心动图测量应为这两个品种以及同一品种克隆的高危新生犊牛的研究和临床评估提供有用数据。
