全國中小學科展

動物學

溫變性轉(孵化條件對宮廷雞性別的影響)

目前生物學知識認為雉科鳥類的性別,在卵受精後即決定(WZ型),不受環境的影響,但是在本組一連串的實驗中發現,雉科鳥類的性別與孵化的溫度變化有非常大的影響,一般宮廷雞的孵化條件在濕度55%RH及溫度98℉~99℉,在此孵化條件下宮廷雞的子代♀:♂=1:1,若溫度降為97℉的孵化條件下所得子代♀性佔93%,倘若溫度升高為100℉的孵化條件下所得子代♂性佔92%,可見在比正常孵化溫度高的環境下宮廷雞的受精卵會轉變為♂性,而比正常孵化溫度低的環境下孵化的宮廷雞受精卵卻會轉變為♀性,本實驗續做了六代,結果大致相似,由此可以證明控制孵化溫度可以改變宮廷雞的性別,這一行為,可能與Z染色體上一個溫度依賴型的連鎖基因(DMRT1)之表現有關。 ;The temperature of hatching can affect Chinese silkys's sex It is now established that the sex of Pheasants is determined when the egg is impregnated, rather than by environmental factors. However, in a series of experiments, we find that the sex of Pheasants is strongly related to the temperature of hatching. In the normal hatching condition (humidity:55% RH ,temperature: 98.5℉), the ratio of female and male offspring of Chinese silkys is 1:1. If the temperature is lowered to 97℉, the female offspring occupies a proportion of 93%. If the temperature is raised to 100℉, the male proportion will reach 92%. We can thus derive the conclusion: the impregnated eggs of Chinese silkys will be transformed to male at a temperature higher than the normal one, while a lower temperature than the normal one will cause the impregnated eggs to be female. The experiments have been conducted through six generations of Chinese silkys, and the results are practically the same. This indicates that temperature changes can affect gender, This may be related to a Z-linked of DMRT1 gene on the DNA, which is temperature-dependent.

達文西「蜜」碼-蜜蜂的視覺經驗與圖形辨識

蜜蜂(Apis mellifera) 可以透過視覺經驗的累積與學習,增加辨識影像的正確率,這種透過先前學習過的經驗而增進視覺辨識的能力,與一般所熟知在視覺上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。 \r 我們以Y型迷宮進行蜜蜂的行為實驗,制約訓練蜜蜂辨識文字影像。蜜蜂能在訓練後成功地辨識文字,並建立所謂top-down process的現象:無法直接辨識複雜的文字影像→經過提出的簡單影像特徵進行訓練後→能顯著地辨識原來的複雜影像。可見蜜蜂能夠藉由經驗中的提示訊息辨識影像。 \r 若以「提示形狀」、「提示位置」、「提示正確端」及「提示錯誤端」等不同影像特徵進行實驗,則發現蜜蜂會擷取形狀或正確影像的訊息,在記憶中形成較深刻的經驗,增強辨識能力。 \r 蜜蜂能夠辨識文字,且能在短時間內擷取重要的影像特徵,做為執行top-down process的經驗。蜜蜂只用不到1 mm3的腦部處理複雜的視覺訊息,牠們的行為與神經機制值得我們繼續深入探討。

以數位像素分析法探討兩棲類變色行為之研究

本研究是以數位科技改良生物實驗上的傳統比色法,並探討中國樹蟾及台北樹蛙的變色行為。有些兩棲類有變色行為,這是眾所皆知的現象,過去一向採用比色法判斷生物體的體色變化;然而,以人眼去測定色差,會有相當大的主觀誤差。本研究及是探討以數位科技量化並比較實驗對象的變色情形。在研究過程中,用電腦量化數位相機所拍攝的影像,以像素的方式呈現出來,得以取的準確且客觀的實驗數據,並加以解析,也經由此一實驗方式,交叉比較中國樹蟾及台北樹蛙在不同環境和不同時間下的變色情形。結果顯示:樹蛙變色和環境顏色及時間有密切關係,且在短時間內以數位量化的方式解析其變色行為的方法極為可行。The purpose of this study is to investigate the color variation behavior of tree frogs using an image processing technology. It is known that some of the amphibians have the ability to change their skin color under different circumstances. In the past, a conventional “color comparison” method was frequently used whenever it comes to analyzing the color variation of organisms. However, it is realized that evaluation of color difference by human eyes is extremely unreliable. An advanced image processing technology is thus suggested to quantify the variation of skin color of tree frogs under different conditions in this experiment. Accurate quantification can be determined from the pixel number of exhibited digital images during the experiment. The color variation of different species of frogs (Hyla chinensis & Rhacophorus taipeianus) is also compared under different parameters. It is found that the color variation of tree frogs is closely related to the color of back ground as well as time. The proposed digital quantification technique has been successfully demonstrated to be an effective method for analyzing the color variation of frogs within a very short time.

果蠅單眼的發育調控基因之篩選

在果蠅成蟲的頭頂上方三顆可以感光的單眼(ocelli),其構造和複眼有顯著的差異,但單眼及複眼在果蠅幼蟲時期,皆從一片特別的組織eye-antenna disc發育而來。而且目前已知會表現在單眼的一些特定基因,也是會調控複眼發育的基因,如sine oculis (so),eyes absent (eya) 等。但到底是哪些特定的基因決定了單眼與複眼的差異,目前並不是很清楚,因此我想探討果蠅單眼細胞在發育過程中,有哪些特定的基因會調控果蠅單眼的生成與變化。 本實驗主要是利用果蠅研究上常使用的基因表現系統(UAS-GAL4 system)進行研究,我們挑選許多和複眼發育相關的基因、胚胎生長發育相關基因進行表現,觀察其單眼性狀有無變化,篩選出會影響單眼發育的相關基因後,再進一步研究此基因的可能作用機制。 從實驗的結果中發現當表現ras及Egfr的顯性抑制型 (rasDN, EgfrDN)時,在掃描式電子顯微鏡下可觀察到三顆單眼會明顯變小。而在幼蟲時期的eye-antenna disc,利用免疫螢光染色以及雷射共軛焦顯微鏡觀察到當表現rasDN、EgfrDN時, 單眼標記基因(marker gene) Eyes absent (Eya)表現的強度顯著降低。再加上已知ras為Egfr的下游基因,綜合這些結果,我們認為Egfr-Ras 以及其下游基因的訊號傳遞對於單眼發育是很重要的。 另外在視網膜電流圖(electroretinogram)的實驗當中,發現Egfr, ras訊息傳遞被抑制的果蠅單眼在對光線刺激的反應強度比起正常的果蠅下降許多,因此可推論Egfr, ras的訊息傳遞不僅會影響單眼的發育,也會影響單眼的正常感光的功能。

新竹北埔冷泉蝦子之研究

因特殊的地理關係而形成奇特之新竹北埔冷泉,其水溫長年偏低且水質特殊。本研究報告主要在探討生長於冷泉中的蝦子其所屬物種、生命力、生態及新竹科學園區所排放的廢水對其生存之影響等議題。為能獲得科學與客觀性的結果,我自己設計了實驗以及適當的實驗步驟來幫助我找到解答,這也讓我對問題有深入的瞭解。我發現這些黑殼沼蝦,螯足各節間有粗糙橙斑,可以耐7℃的低溫,靠嗅覺覓食,小蝦在前4 週呈快速的成長,污水中的蝦子短期內一定死亡,從基部斷肢才能有再生能力等結果。茲條列所探討的問題如下:1.探討北埔冷泉蝦的身體構造與其功能。2.了解北埔冷泉蝦和一般食用蝦身體構造的差異性。3.探討北埔冷泉蝦的生長環境與其行為之關係。4.探討北埔冷泉蝦的食性。5.探討北埔冷泉蝦的覓食行為。6.探討北埔冷泉蝦與養殖蝦存活率的差異性。7.探討北埔冷泉蝦與養殖蝦的耐溫能力。8.瞭解北埔冷泉蝦的雌、雄判定。9.探討北埔冷泉蝦交配與孵卵方式。10.探討北埔冷泉蝦小蝦的成長曲線。11.探討不同水質對北埔冷泉蝦的影響。12.探討北埔冷泉蝦斷肢後的再生現象。經由這次的研究,讓我對北埔冷泉蝦子的身體構造、生長環境、覓食行為、耐溫能力、交配與孵卵、小蝦的成長、斷肢後的再生、甚至水質對蝦子生存之影響等等已能深入瞭解。除此之外之外,更重要的是從疑問的產生,實驗方法與步驟的構思、做實驗的過程,及獲得可信的結果,再再使我深刻體會到科學精神的真諦。Bei-Pu cold spring of Hsinchu was formed due to the unique geographical feature. This paper investigates the species, livability, ecology and affection of water quality of the wildlife shrimps that live in this special environment. I design my own experiments and suitable procedures to help me to get the scientific and objective results. The research topics on Bei-Pu wildlife shrimps are listed below. 1. Body structure. 2. Distinguish bred and this wildlife shrimp. 3. Growth environments and its behavior. 4. Foods. 5. Hunting 6. Livability. 7. Tolerance of low temperate. 8. Male and female. 9. Mating and incubating. 10. Growth characteristics. 11. Affection of water quality. 12. Limbed and re-generation. These crayfishes can survive under 7℃. Hunting behavior is guided by olfaction other than vision. They grow rapidly in the first 4 weeks. Regeneration occurs only from the joint. Water quality is vital to them. From this study, I understood the species, hunting, mating, incubating, growth, temperature tolerance and regeneration of this wildlife shrimps. Moreover, I deeply appreciate what real scientific essence is through defining the questions, designing the experiments, procedures and obtaining the results finally.

蟋蟀的聲音分析與聲音行為探討

蟋蟀聲音與行為的關係密不可分。取北部四種蟋蟀樣本,以數位錄音筆錄製及電腦軟體分析蟋蟀的聲音,並用PCR技術萃取蟋蟀的粒線體DNA(16S)加以分析,藉此和傳統的形態學分類相互比較。結果發現蟋蟀聲音的頻率特性中主頻率的差異在親緣遠近有關聯性,但聲音的時間特性方面則沒有特定關聯,不過聲學分析圖仍可作為單一種的鑑定指標。此外,研究發現此4種蟋蟀的聲音頻率範圍有重疊現象,但主頻率、脈衝比、唧聲率及唧聲長不同,推測雌蟋蟀應是綜合這些特性辨別同種。另一方面,以黑蟋蟀作為研究對象,進行干擾實驗,觀察並繪製出其聲音行為模式; 並將此作為對照,結果發現蟋蟀的生殖行為主要受到雄蟋蟀的聲音支配,而雄蟋蟀則以嗅覺辨別雌蟋蟀位置,決定下一步行動,與視覺較無關係。 Cricket's voice is closely related to the behavior. We select four species of crickets from the northern Taiwan to study the acoustic and mating behaviors. The digital sound recorder and acoustic software are used to analyze their acoustic characters. Furthermore, the PCR technology is used to amplify and sequence parts of mtDNA sequences and the results were compiled as the comparison to the traditional morphological character. The result shows that the resolution in acoustic characters of main frequency, pulse number, chirp rate, and the length of chirp are different among four species, though the minor frequency pattern is overlapping. Moreover, we find that frequency characteristic difference among four species is partly related to their phylogenetic relationship, yet is not seen in time characteristic. It is obvious that difference of acoustic behavior can be regarded as identified index among species. Results of acoustic analysis impel us to infer that the female crickets take the comprehensive acoustic behavior to distinguish their specific male. In addition, behavior pattern and model of Gryllus bimaculatus are established as the comparison of interfering experiment is undertaken. Which results suggest that the mating behavior in cricket is dominated by males’ acoustic behavior, and is initiated by male’s olfactory sense rather than that of sight.

蝴蝶眼斑的探討

在眾多的蝴蝶中有不少是具有眼斑。傳統上認為眼斑的功能是驚嚇天敵或欺騙天敵。有關眼斑本身結構的瞭解很少。我們利用臺灣及馬祖產的蝴蝶,分別記錄圖鑑上峽蝶、眼蝶及灰蝶合計 60 種以上,以及鳳蝶幼蟲七種的眼斑特性。記錄的眼斑特性包括數目、組成的色彩結構,以及記錄眼斑在翅的腹面或背面明顯。進一步測暈孔雀峽蝶、台灣波眼蝶、蘇鐵小灰蝶等三種蝴蝶的眼斑和翅面積。眼斑在腹面及背面都有,但以腹面明顯者佔多數,而眼斑數 l 一 7 個都有,在後翅者佔多數。眼斑慕本是由數個同心圓組成,分別為輪廓、眼白、虹彩及障孔。在峽蝶及眼蝶的結構都相當完整,輪廓為褐或深褐,眼白為黃色為主,虹彩都為黑色或深褐色,障孔為白色或淡藍色。在灰蝶的眼斑較不完整,大都輪廓不清晰,眼白的黃色或橙色部份比例高,但都缺少障孔。幼蟲有眼斑成蟲不一定有。鳳蝶的幼蟲( 8 種)都為綠色,其眼斑輪廓黑色,眼白為白色及紅色但明顯比上述成蟲的眼斑之眼白部位要小,而黑色的虹彩都很大。幼蟲的障孔為白色的細線形,我們認為這和立體形狀的幼蟲及成蟲平面翅的差異所造成,在文中也討論到水棲蝶魚的眼斑和蝴蝶眼斑的差異。眼斑和翅面積的相關分析結果變異很大,在統計上正相關及負相關都有。眼斑數目的不定及和翅面積並沒有一定關係,我們討論到蝴蝶的眼斑在不同種類有些可能有求偶生殖上的功能。這方面值得科學家大量投入研究。Quite a few species of butterflies have colorful eyespots on their wings. The main functions of these eyespots were considered to startle or deceive predators by most scientific researchers. In fact, only limited literatures dealt with the basic structure and color patterns of butterfly eyespots. The purpose of this study is to study the basic structure and color patterns of these eyespots. We measured the surface area of eyespots v.s. wings from specimens. From the color plates of Taiwan and Matsu butterfly field guide, we recorded the eyespots either on ventral or dorsal side of wings, and the color patterns for more than 60 species. \r The number of eyespots on wings varies from I to 7 among individuals we checked. Majority of eyespots were found on ventral side of wings. The basic structure of eyespots were formed by I to 3 concentric circles, i.e., outboundary, cornea, iris and pupil . Pupil was not found in certain species. The color in cornea section is yellow and in iris is black or dark brown. The contrast in these two areas is quite prominent just as the contrast showed in warning coloration of after animals. The pupil is either white of light blue. Caterpillars with eyespots were found in Papilionidae, their adult stage were without this character. We checked 8 species of caterpillars, their basic structure of eyespots were similar to other butterflies, with cornea, iris and pupil. The cornea is either red or white color, and the iris is black in colors. The ratio(iris/cornea) is much higher in caterpillar than in butterfly. The pupil is a thin thread shape instead of a tiny spot like the one in butterfly wings. We discussed the difference of pupil between juveniles and adults from the aspect of dimension structure of a subject. In the paper we also discussed the difference of eyespots between butterfly and butterfly fish in the coral reef. Base on the no significant relationship between the surface area of eyespots and wings. We suspect that butterfly eyespots may have another function, such as intersexual selection between males and females beside startling and deceiving predators.\r

Characterization of the Zebrafish ghost(gho) Mutant

廣鹽性吳郭魚氯離子調節機制- - - NKCC在氯細胞中扮演之角色

本實驗中我們利用廣鹽性吳郭魚進行氯離子調節機制的研究,探討廣鹽性吳郭魚如何能在不同環境中維持體內氯離子恆定,進而適應生存環境。我門想要探討:『是否NKCC 這種蛋白質在淡水吳郭魚MR 細胞中扮演吸收 Cl- 的角色? 如果是,吳郭魚又如何藉NKCC 的調節適應環境中 Cl- 的變化呢?』我們利用細胞免疫螢光染色法、西方墨點法和共軛焦顯微鏡觀察分析NKCC 在不同 Cl- 濃度人工淡水馴養的吳郭魚MR 細胞上的表現量,結果發現 NKCC 分布於頂端細胞膜(又稱為細胞開口),及其附近的細胞質內;環境中 Na+ 濃度的差異對NKCC 在MR 細胞上的表現影響不大,但低 Cl- 環境馴養的吳郭魚,NKCC 表現量都高出其他組很多。顯示NKCC 參與了氯吸收的機制。另一個實驗中,我們將吳郭魚由淡水中轉移至海水以分析它們在適應海水的過程中NKCC 的表現變化。結果發現在馴養初期(16 小時內),圓點狀NKCC 仍然可以在MR 細胞的開口附近觀察到,但到了24 小時後,NKCC 在開口的表現就明顯減少甚至消失,取而代之的是轉移到底側邊細胞膜上的NKCC。此實驗證實了NKCC 這一個與Cl-運送相關的蛋白質,在廣鹽性吳郭魚氯離子調節中扮演了很重要的角色。 Euryhaline tilapia (Oreochromis mossambicus) is capable of maintaining internal ion constant ineither hypertonic or hypotonic environments (fresh water or seawater).MR cells in the gills of tilapia play critical role in absorbing Cl- from fresh water or pumping redundant Cl- from body fluid into seawater. Chloride transporter (NKCC) which distributed in basolateral membrane of MR cells is involved in Cl- secretion of seawater teleost. However, the mechanism of Cl- absorption in fresh water MR cells is still unclear. Whether NKCC is also involved in Cl- absorption and how do tilapia regulate Cl- absorption are the questions this study aim to answer. By using immunofluorescent staining, western blot, and confocal microscopy, the distribution and expression level of NKCC in fresh water MR cells were examined. We found that NKCC is distributed on the apical membrane of freshwater MR cells where is known to be the site for active Cl- absorption of MR cells. We compared the expression level of NKCC in MR cells from tilapia acclimated in high, normal, and low Cl- artificial water for 7 days. The results showed that NKCC is induced by ambient low Cl- , and in contrast suppressed by high Cl- water, indicating NKCC might be involved in Cl- absorption of freshwater MR cells and up-or down-regulated to maintain Cl- uptake constant. In addition, we also examine the expression pattern of NKCC in MR cells from tilapia transferred from fresh water to seawater. Confocal images show that apical expressed NKCC disappear gradually within 24h seawater acclimation and is substituted by basolateral expressed NKCC. This study provides a novel regulatory mechanism of NKCC in Cl- transporter of MR cells.

蜚腸知味-探討不同味覺刺激對美洲蟑螂口器及前腸活性的影響

前饋(feed-forward)是一種於生理反應發生之前,所進行的調節機制,為即將發生的生理作用進行準備。前人對於蟑螂消化道的前饋作用,大多著墨在酵素分泌的調節作用。本研究以美洲蟑螂作為實驗動物,觀察蟑螂消化道中前腸的組織型態,並以肌肉電位圖(electromyography, EMG)的記錄方式,探討探討味覺刺激對蟑螂嗉囊與砂囊肌肉活動的調節作用。我們發現蟑螂的消化道由橫紋肌所構成,有別於人類消化道主要由平滑肌所構成。由EMG的紀錄得知,餵食葡萄糖溶液時,可增加蟑螂嗉囊肌肉的放電幅度;而餵食味精(麩胺酸)溶液時,可增加砂囊肌肉放電幅度,推測葡萄糖與麩胺酸各可引發嗉囊與砂囊肌肉的收縮活動,皆屬於前饋機制的例子;若以清水清洗口器時,亦會引發前腸肌肉的放電行為,推測為清洗口器時引發吞嚥反射所致。