全國中小學科展

動物學

共生性倒立水母(Cassiopeia andromeda)之光生物學研究

倒立水母(Cassiopea andromeda)為一種體內含有共生性蟲黃藻的缽水母類,其傘部收縮運動可引發水流,為水母帶來獵物,同時也是與外界物質交換的重要途徑。共生藻則以自水母體獲得的物質與光能行光合作用,以供應自身與宿主水母之需。本實驗首先探究各種光環境因子(光強度、日週律、不同波長色光)與倒立水母個體大小、飢餓狀態及有無共生藻等因子,對其傘部收縮頻率的影響,進而研究倒立水母異營性攝靪與個體耗氧率等基本能量代謝特徵。研究結果顯示:正常的碟狀體具有明顯的光趨性行為,伽無共生藻的個體則否。水母傘部收縮頻率隨體型的增大而降低,在自然光照與餵靪的條件下,其收縮頻率則有明顯增加的趨勢;反之,黑暗與持續的飢餓狀態,會使其收縮頻率明顯下降。自然光照組的水母個體,其24小時內的收縮頻率呈明顯的日週律變化,伽黑暗組則未見此一現象。以不同色光照射的各組水母,其傘部收縮頻率未見明顯變化,伽各組無共生藻的個體則明顯低於正常的個體。此外,體型較大的個體,其水體過濾作用與清除率(異營性攝靪能力)皆明顯高於小型個體,而且無共生藻個體的清除率高於相同體型的正常個體,暗示其異營性攝靪能力的增加與能量獲得策略的改變。在黑暗中的耗氧率(基礎代謝率),則以正常的個體較高,而且無論正常的個體或無共生藻的個體,其個體單位體重耗氧率皆隨體型的增大而減少,呈現明顯的尺度效應。綜合上述結果可知:光環境因子能明顯影響倒立水母傘部收縮頻率,且可能係透過共生藻的光合作用等相關生理機制進行,進而影響其異營性攝靪與光環境選擇能力。

Thelytokous Parthenogenesis by egg-laying workers in the Black Ant, Ochetellus glaber. (Hymenoptera: Formicidae)

孤雌產雌(Thelytokous Parthenogenesis) 是一種雌性個體未經過交配,自行產出擁有雙套染色體之雌性子代的生殖行為。目前在其他已發表的文獻中,僅有四種亞科的十一種螞蟻採取此種生殖方式,並依照其形式的不同,區分成三種孤雌產雌的類型。本研究主要針對光滑管琉璃蟻工蟻的孤雌產雌行為進行探討,證實未與雄蟻交配過的工蟻,能自行產下具有雙倍體的後代。統計結果指出,超過87%的大型聚落是由產卵工蟻領導,形成缺后聚落,而每一個蟻巢至少會有80%以上的工蟻轉變為產卵工蟻。\r 研究中也發現,產卵工蟻的產卵速率明顯高於蟻后、其子代發育週期亦較蟻后短,顯示出光滑管琉璃蟻缺后聚落以孤雌產雌擴張的優勢。大多數的產卵工蟻在外型上較一般工蟻長,我們能夠在其腹間膜膨大時觀察腹部內加以區分二者。當蟻巢位處於休眠狀態產卵工蟻的表面碳氫化合物與內部腺體的組成成分與一般工蟻有別,而解剖後可在其微卵管中發現卵。此外,兩者在分工上,產卵工蟻除了確保聚落的繁衍,還需照顧其手足;一般工蟻則負責巢外的覓食與警戒等工作。\r 本研究首次記錄了琉璃蟻亞科行孤雌產雌的行為,而這種對於孤雌產雌與有性生殖並行之蟻種的探討,也?孤雌產雌創立了一個新的研究方向。

估算土棲螞蟻聚落的新方法----以黑巨蟻(Camponotus friedae)為例

Estimated colony size is a basic work to count population of social insect up. It is not easy to measure any natural population accurately, in this respect, social insects here some advantages and some disadvantages over non-social ones. Previous studies have focused largely on the experimental colony of ants, such as Lasius niger, Myrmica sabuleti and Formica rufa, in the artificial nest. Furthermore, base on the division of labor, traditional Mark-Recapured Methods can not be used to measure complete colony of ant correcty. Here, we show that new method has be set up to calculate the colony of the ground black-giant ant, Camponotus fruedae,with a new indicator, ant hill. Predictions about the division of labor introduced to amend the formula of estimated population are discussed.本實驗探討黑巨蟻的蟻丘之形狀和生物意義,並分析利用何種方法能估算最準確的聚落大小。利用幾何圖形證明黑巨蟻會築似圓的蟻丘,並利用標識捕捉法的Petersen method(又稱為Lincoln index)、Schnabel method 和蟻丘大小重量,來推算黑巨蟻聚落之大小。發現黑巨蟻會築似圓度90%的蟻丘,而且標識捕捉法的Petersen method(又稱為Lincoln index)、Schnabel method 並不能精確的推算出黑巨蟻之聚落大小;應使用黑巨蟻之蟻丘的重量當作參數來推算,才不會忽略幼蟲的存在。

圖變「蜜」碼─蜜蜂視覺經驗的擷取與top-down process

視覺經驗訊息的top-down process能增強動物對影像的辨識能力,這種透過先前學習過的經驗而增進視覺辨識的能力,與一般熟知視覺是由眼睛將影像訊號傳至大腦進行辨識的過程恰好相反,因此被稱為top-down process。本研究以Y型迷宮進行訓練蜜蜂的行為實驗,首先提供無法直接辨識的複雜影像,再經過提出的簡單影像特徵進行訓練後,再以原先無法直接辨識的影像予以測試,證實蜜蜂也具備這樣top-down process訊息的能力。此外,藉由改變各種視覺影像特徵,進一步探討這樣的視覺訊息可能傳遞路徑。藉由擷取、篩選後的重要影像訊息復甦相關視覺經驗以增強辨識能力,有助於蜜蜂以更有效率的方式訪花。蜜蜂大腦體積不到1 mm3,卻有處理如此複雜視覺訊息的能力,其行為與神經機制實值得深入探討。

Ethidium Bromide 對p53 基因缺陷老鼠致癌影響

p53 蛋白是一種轉錄調控因子,其在抑制癌症的形成扮演很重要的角色。已知的報告顯示它能影響下游特定蛋白表現進而調控細胞週期或促使細胞進行凋亡作用。如此作用機制對於可能癌化的細胞在生物體造成傷害之前能被先行消滅,因此正常的p53 蛋白存在與否,對癌症的產生有很大的影響。 根據上述結果,我們想分析不同表現量的p53 是否對於致癌藥劑-EtBr所引發的癌化細胞有所影響。所以我們設計實驗,將具有正常表現量p53 蛋白的老鼠(p53+/+)與僅能表現少量p53 蛋白的老鼠(p53+/-),均塗以等劑量之致癌藥劑EtBr於其大腿皮膚上,觀察其致癌情形的差異。實驗結果發現 : 在塗EtBr 的14 隻p53+/-老鼠中,有3 隻出現了組織病變的症狀,包括脾臟腫大,淋巴組織長出腫瘤,而其他對照組(一)塗EtBr 的p53+/+老鼠,(二)不塗EtBr 的p53+/+老鼠或(三)不塗EtBr 的p53+/-老鼠都沒有產生異常的症狀。因此根據上述實驗結果進行推論,發現經EtBr 的刺激後,p53+/-的老鼠的確較其他的老鼠更容易得到癌化細胞。;p53 is a transcription factor that plays an important role in suppression of tumorgenesis. Previous reports showed it regulates cell cycle and enhances cell apoptosis by effecting specific proteins expression. By this way, the problematic tumor cell can be deleted to protect organism from tumor damage. According above conclusion, we are interested to know whether p53 plays a role involved the carcinogens-EtBr induced tumorgenesis. We compared the differences of tumorgenesis between mice express normal (p53+/+) or low (p53+/-) expression level of p53 proteins when they are smeared equal amount of EtBr on skin of thigh. In here, our results show three of fourteen p53+/- mice had pathological changes, containing spleen enlargement and lymphoma. However, other three comparisons, smear p53+/+ mice with EtBr (1), without EtBr (2) or p53+/- without EtBr(3), are normal. Therefore, We suggest that p53+/- mice are easily to obtain tumor than p53+/+ mice after EtBr treatment.

南爭北鬥之壁虎大戰一蝎虎與無疣蝎虎種間競爭程度之評估

無疣蝎虎(Hemidactylus bowringii)與蝎虎(Hemidactylus freuatus)分類上屬蜥蜴目守宮科蝎虎屬,為本島住家附近常見且生態地位相近的壁虎,近年來因人為因素使原本有地理區隔的兩種壁虎在北部地區產生共域現象。本研究利用問卷來調查兩種壁虎分佈狀況,並用「體型大小」、「食物競爭能力」兩種指標,設計實驗評估種間競爭程度,來探討兩種居家壁虎種間競爭程度。問卷調查及物種採集結果顯示,在台北市各行政區確實存在共域現象,且分佈數量互有消長。體型大小比較上,蝎虎體型較無疣蝎虎稍大,但在統計上無顯著差異。食物競爭能力強弱比較上,以斷尾後尾巴增長量為指標,結果兩者大致相等,無顯著差異。綜合以上研究結果,顯示兩者共域後會出現種間競爭現象,程度大致相等,有互相消長現象。Hemidactylus bowringii and Hemidactylus freuatus are commonly seen in Taiwan, and their habitats are very near the area people live. Recently, two species have inhabited the same or overlapped geographical areas in northern Taiwan. This sympatric phenomenon resulted from the geographical isolation being broken by people. This research investigated their distributions in Taipei city by using questionnaire, and evaluated the degree of interspecific competitions by using indexes of the body size comparison and the food competition to design our experiments.According to results of questionnaire and animal sampling, two geckos did inhabit closely in some areas in Taipei city, and their population distributions were changing with time. According to the result of the body size comparison, Hemidactylus freuatus is bigger than Hemidactylus bowringii. But there is not a statistically significant difference between two species. The degree of food competition of two species was all square. In summary, it was occurred the interspecific competition between Hemidactylus bowringii and Hemidactylus freuatus, and the degree of competitions was almost equal.

足下天地大,掌中有乾坤─橙斑大龍蝨抱握足的形態與吸附力

有別於大多數龍蝨抱握足上所具有的圓形吸盤,橙斑大龍蝨具有特殊的掌形吸盤,吸盤內具有四排舌墊狀構造。藉由吸盤吸附與脫離機制的探討,發現吸盤內跗節的關節與舌墊在吸附時會發生形變以增加吸盤的吸附,而舌墊的不對稱性構造則可以使吸盤在脫離時較為容易。我們也利用自製的實驗裝置測量吸盤在水中的吸附力,結果顯示吸盤吸附力的主要來自於舌墊,其切向力大於法向力,且切向力具有方向性,推測與舌墊之不對稱性有關。這種掌形吸盤除了可重複在水中進行吸附之外,也具有方便脫離,以及可吸附不規則平面等特性,在仿生學上的應用極具潛力。

酒精對斑馬魚胚胎眼睛發育的影響

長期以來,臨床研究發現會影響人類胚胎的正常發育,造成胚胎畸形、成長遲緩等現象,稱為胎兒酒精症候群(fetal alcohol syndrome),但是其病理機制仍不清楚。最近的研究發現斑馬魚胚胎對於酒精有非常靈敏的反應,出現明顯的發育異常現象,例如心臟膨大、眼睛縮小、骨頭變形等現象,與人類胎兒酒精症候群相似,顯示斑馬魚非常適合作為研究胎兒酒精症候群的模式動物。在本實驗中,我們針對酒精影響視網膜神經發育的現象進行探討,並且也利用基因晶片篩選出胚胎發育時期受酒精影的的基因轉錄子,藉以了解酒雞造成胚胎畸形發育的機制。實驗結果顯示在眼睛發育過程中,1.5% 酒精浸泡會抑制視網膜神經細胞的分層(Lamination),而進一步利用RNA定位雜交的方式以眼睛的標示基因rx1、pax6b、six3b、alpha-crystallin、rho、neuroD、huC觀察他們的表現,發現酒精會減少視網膜神經細胞的分化,造成眼睛發育的缺陷。在基因晶片的分析中,我們發現酒精處理會抑制許多控制眼睛發育的基因調控子的表現,包括了crx、rybp、irx4a、optx2、rx1、brn3b1 與 vsx1等,此外約有16%的眼睛相關基因液受到酒精的抑制,遠高於其他基因受抑制的比例,顯示眼睛是酒精傷害最嚴重的區域之一。我們從實驗結果得知酒精並未對胚胎發育初期眼睛的發育造成明顯的影響,但是隨後由於控制細胞分化的幾個重要基因受到酒精抑制作用,造成視網膜神經細胞的分化停止,引起眼睛的異常發育的情況。It was known that prenatal alcohol exposure may cause serious birth defects and developmental disabilities. The molecular mechanism of this fetal alcohol syndrome still remains unclear. Here we used zebrafish embryo as a model to investigate the toxic effect of alcohol in retinal development. The histochemical analysis revealed that the cell lamination was prohibited by alcohol incubation. It appears that the retinal cell differentiation was inhibited. As revealed by whole mount RNA in situ hybridization, it appears that the transcription of a number of retinal-related regulatory genes, including rx1, pax6b, six3b, alpha-crystallin, rho, neuroD and huC, were all inhibited in zebrafish embryo by alcohol exposure. The transcriptional profile of alcohol-exposed embryos was also compared with normal embryos by microarray analysis at different stages. It appears that 16% of retinal-related genes were all repressed by 1.5% alcohol incubation, including several retina-related transcriptional factors, including crx, rybp, irx4a, optx2, rx1, brn3b1and vsx1. Our results suggest that alcohol did not interfere the early development of the eye, but has inhibited the final cell differentiation of retina cells. This study helps us understand the molecular mechanism of alcohol-mediated retinal malformation.

安德遜繩虎生活史、行為能力及棲息地之研究

安德遜蠅虎的卵期和幼蛛期共約需 22~26 天,需經歷 6 齡(6 次脫皮)而成年,每齡需要時間為23~32 天,從卵期到成蛛約3~4 個月左右,成蛛約可再活 3~5 個月,為不完全變態。安德遜蠅虎喜歡在食物充足和陰暗的草叢和牆壁底層活動,能適應的溫度範圍在 15~33℃之間。安德遜蠅虎的行為項目目前已知 14 種,其中 4 種與捕食行為有關(例如:頭胸部升降、潛行、撲擊、迂迴),3 種與爭鬥行為有關(例如:Z形舞蹈1、前足斜舉、奔逃);5 種與求偶行為有關(例如:觸肢擺動、前足斜舉、繞行、Z 形舞蹈 2、交尾) 。但牠不獵捕比自己體型過大的獵物,主要以小型蠅類或彈尾蟲為食,其捕食獵物主要靠視覺或感覺毛,中前眼最遠可看到超過12cm距離的東西,跳躍力最遠可跳出15cm 的距離。對於蠅虎的分佈區域就觀察提出【蠅虎集中發散推論】 :一區域內的各種蠅虎,必有其集中地。各種蠅虎由其集中地向外發散、擴張形成發散地,並與其他種蠅虎勢力範圍重合,形成多種蠅虎共存的共存區。Hasarius adansoni’s egg development and postembryonic development require 22~26 days. It takes 6 stadiums to become adults. Every stadium needs 23~32 days . The adults can live to about 3~5 months . There are 3~4 months from egg development to adult. Hasarius adansoni like to move in grass and at the bottom of wall where there is plenty of food and no light.The scope of temperature is 15℃ to 33℃.There are 14 elements of behaviors known for Hasarius adansoni, including 4 predatory elements(such as Raise andlowered cephalothorax、Stalk、Leap and bit、Detour) , 3 agonistic behavior elements (such as Zigzag dance 1、First leg erect、Suddenly run and leap), and 5 courtship behavior elements(such as Palp waving、First leg erect、Circular detour、Zigzag dance 2、Copulation).But they don’t catch captures which are bigger than themselves;their main captures are little flies and Homidia sp. Relying on their vision and sensation hair,Hasarius adansoni’s Anterior Median eyes can identify for up to 12cm;long jump can for up to 12cm. The inference of jumping spider’s distribution could be that different species of jumping spiders in an area are sure to have their respective center habitats. They spread from the center habitats to disseminated areas. Then they overlap with those of their species and form a shared section of multiple species.

溫度與光週期對淡黃蝶的影響

為了了解淡黃蝶Catopsilia pomona無紋型crocale-like及銀紋型pomona-like中間受到環境因子的差異。先比對兩型的粒線體DNA,之後模擬夏季和冬季自然環境進行實驗。得知兩型為同種。另一方面進行溫度和光週期的實驗,顯示淡黃蝶幼蟲和成蟲雌雄個體各部位會受到此兩環境因子的影響。In order to realize if Catopsilia Pomona and Catosilia crocale are the same species, we analyzed and compared the DNA sequences of Mitochondria, and the result revealed they are indeed the same species. Then we observed the developmental process of the butterfly, and inspected the effects of different factors: photoperiod and temperature were shown to affect the phenotype of the butterfly; lower temperature and shorter day resulted in phenotypic shift from crocale-like to pomona-like, and vice versa. Also, the conflicting factors produced intermediated form. (e.g. lower temperature with longer day) Not only changed the phenotypes of adult with photoperiod and temperature, those of larvae also did. However, the mechanism how photoperiod and temperature affect the phenotype of the butterfly is unknown.