异育银鲫A+系和F系肌间骨的比较分析

摘要

研究采用常规测量法和解剖法,并结合CT透视,比较分析了异育银鲫主养品种"中科3号"(A+系)和候选新品系F系的肌间骨的数目、形态和分布.结果表明,6月龄和18月龄异育银鲫F系平均总肌间骨数分别为71.8±2.9和83.3±1.4,均极显著少于相应月龄银鲫A+系总肌间骨数目(78.6±3.9和87.0±1.5)(P<0.01).并统计了2个品系的每一肌节的平均肌间骨数目,6月龄和18月龄异育银鲫F系的每一肌节的平均肌间骨数目极显著少于相应月龄银鲫A+系(P<0.01).银鲫A+系和F系均有髓弓小骨和脉弓小骨,没有椎体小骨.6月龄和18月龄银鲫F系髓弓小骨的平均数目为48.2±1.1和55.8±0.52,均极显著少于相应月龄银鲫A+系的髓弓小骨(53.7±1.6和58.7±0.5)(P<0.01).异育银鲫两个品系的脉弓小骨数目差异不显著;2个品系均具有"I"形、"卜"形、"Y"形、一端多叉形、两端两分叉形、两端多叉形和树枝形7种类型的肌间骨,髓弓小骨比脉弓小骨数量多且形状复杂.随着月龄的增长,2个品系具有的总肌间骨数目以及复杂肌间骨数目均增加.6月龄和18月龄银鲫F系躯轴上肌节间的复杂"Y"形髓弓小骨数目均比相应月龄的银鲫A+系少,而简单的"I"形髓弓小骨数目比相应月龄的A+系多,表现出一种有利于食用的优势.研究结果为异育银鲫候选新品系F系提供了一个品质评价指标,同时也为后续进行异育银鲫肌间骨遗传改良提供了形态学基础资料.%Allogynogenetic gibel carp is a joint name of a series of clone strains bred from the gibel carp (Carassius gi-belio Bloch). The numbers and distribution of intermuscular bones (IBs) are valuable economic traits. In this study, we compared the differences in number, morphology and distribution of IBs in clone A+ and clone F of an allogynogenetic gibel carp. The average numbers of clone F IBs at six months and 18 months are 71.8±2.9 and 83.3±1.4, respectively;both numbers are significantly less than those of clone A+ (78.6±3.9 and 87.0±1.5) (P<0.01). Similarly, the average numbers of clone F IBs within each sarcomere at 6-month and 18-month are remarkably smaller than those of clone A+. Both clone A+ and F have epineuralia bones (ENBs) and hypomeralia bones, and no epicentralia bones. The average numbers of clone F ENBs in the left body side at 6-month and 18-month are 48.2±1.1 and 55.8±0.5, respectively; both numbers are significantly less than those of clone A+ (53.7±1.6 and 58.7±0.5) (P<0.01). There was no difference found in the epipleural bones (EPBs) of clone A+ and clone F. The IBs of these two clone strains are divided into seven shape categories, including non-forked (I), one-end-unequal-bi-fork (卜), one-end-equal-bi-fork (Y), one-end-multi-fork, two-end-bi-fork, two-end-multi-fork, and tree-branch types. Generally, both numbers and morphological complexity of ENBs are higher than those of EPBs. The numbers of total IBs and IBs with complicated shapes are positively related with age. In the trunk on axis, clone F has fewer "Y" type ENBs and more "I" type ENBs than those of clone A+, indica-ting that clone F exhibits an improved economic trait. Therefore, our results provide an evaluative criterion for a novel strain (clone F) and basic data for genetic improvement of IBs in gibel carp.