| 摘要: | 動物的體型大小以及不同身體部位的異速生長會受到許多的環境因子所影響而能當成是適應當地環境後的結果，且這些因子也同時去影響其他的性狀，像是身體表皮顏色。在本篇論文以牽牛花果蠅和高山果蠅兩姊妹物種為研究對象，利用翅膀長度、翅膀寬度、前足腿節長度和前足脛節長度等四項測量值作為體型大小指標，探討兩物種自然族群的體型大小之差異、地理分布和遺傳性。兩種物種在不同的族群都有體型大小的區別，在台灣的黑色體色牽牛花果蠅體型比在爪哇與蘇門答臘的棕色牽牛花果蠅大，而大致上分佈於較高緯度、較高海拔地區的族群有較大的體型。此外我們也發現到的翅膀的比例(翅膀長/翅膀寬)的變化程度比前足的比例(腿節/脛節)的變化程度小，可能維持翅膀的形狀對他們來說比較重要。另外我們發現到飼養在實驗室的單雌品系也有體型大小的差異，顯示他們為了適應不同的野外環境而在基因背景上已有所差異。並且我們發現到體型大小和體色有關聯，代表控制這兩個性狀的遺傳因子可能有遺傳連鎖或是基因多效性。;Body size and allometry of body parts in animals are subjected to both environmental perturbation and natural selection for local adaptation, and also interplay with other traits, such as body color. Here, we used Drosophila elegans, which exhibits black or brown color morphs in the north and south of its species range, and Drosophila gunungcola, which exhibits black color morphs, as models to study the relationship between local environment and body size, measured by several body length parameters (wings length, wings width, femur length, and tibia length). Significant variations in body size were found in the natural populations in both species. In D. elegans, black-morphed flies exhibiting from Taiwan are larger than brown-morphed flies from Java and Sumatra. Overall, the body size of populations from higher latitude or higher elevation were found to be larger. Also, we found that the wing ratio (wing length/wing width) is less variable than the foreleg ratio (femur/tibia), suggesting that the maintenance of certain wing shape is more important. In addition, the body size of isofemale lines are significantly variable, indicating that both the genetic and environmental variations contribute to the body size variation found in natural populations. Furthermore, the body color and body size in recombinant inbred lines of D. elegans were found to genetically correlated, suggesting that these two traits may be influenced by closely-linked or pleiotropic genes. |
