全國中小學科展

動物學

探討黃胸錐腹蜾蠃交尾、做巢行為對產卵與育幼之影響

本研究探討黃胸錐腹蜾蠃(Delta pyriforme)交尾、做巢、產卵、育幼等生殖行為。結果一雌雄壺蜂平均性成熟為 77±10.8、63.7±5.7 小時,交尾結合只有 11 秒。結果二壺蜂用大顎與前足以 0.8×10-3m/s 速度拍打泥球,讓巢固定成型,結蜂繭後巢硬度達 4269gw。結果三受微風影響卵搖 9.3 次/s,此時卵柄的張力對卵做出 164.3nkg.m/s 衝量值,當衝量越大、卵搖晃時間越長、停下時間要越久。結果四壺蜂會依不同體型獵物,施予不同的力搬運回巢,被麻痺獵物血液流速為 1.64~1.13cm/s,氣孔被打開 494%,以延長獵物壽命,有助於壺蜂幼蟲攝食,達到育幼後代的目的。

Sequentially bidirectional gastrovascular flows in highly branched digestive tracts of panocerid flatworm

Examination of the predation behavior of polyclad flatworms is extremely rare. This study collects Paraplanocera oligoglena, the most common species in Taiwan. Tank-based feeding experiments reveal that Paraplanocera oligoglena can prey on several species of gastropods, such as sea snails and sea hares. Predation behavior encompasses attack, invasion and ingestion periods. This research pioneers the use of stained clam and static image analysis to observe the highly branched digestive system of flatworms. The sequentially bidirectional flow of gastrovascular cavity is first found in polyclad flatworms by the post-stain active tracking technique. Measuring peristalsis movement in inward and outward directions and segmented movement, the contraction frequencies are roughly the same in subsequent order of given branches. Confirmation is provided that the circular membrane-like muscles within the digestive tract are the main driving force for transporting and mixing food. The food dyeing technology used in this experiment also provides the possibility of future research on food chains in the wild.

探討果蠅神經膠細胞核的遷移機制

細胞核是真核細胞內最大且至關重要的細胞結構之一。其具體位置在各種細胞中可能有所不同。為了深入了解細胞核位置對於細胞功能的影響,我們選擇以果蠅幼蟲眼疊為研究對象,探究細胞核在神經系統發育過程中所扮演的角色。神經系統在生物體中扮演著極為關鍵的角色,包括神經元和神經膠細胞。如果失去神經膠細胞,將導致神經退化或死亡。在我們的研究中發現,神經膠細胞核在其發育過程中會發生大規模的內部移動。為了限制神經膠細胞核的移動,我們利用了果蠅作為研究動物,並應用了果蠅常用的 GAL4-UAS系統和GrabFP技術,這使得我們能夠限制神經膠細胞內細胞核的移動。我們的實驗成功證明,限制神經膠細胞核的移動會影響神經細胞的軸突發育,但不會影響神經細胞 R1-R8 聚叢的發育。未來,我們計劃將 GrabFP 技術應用於研究不同胞器在細胞內相對位置對其功能的影響。

Straw manufacturing for epidemic prevention

Recently,thefeedpricesforlivestockfarmshavebeencontinuouslyincreasing, while the prices of calves have been declining, leading to many livestock and dairy farms facing financial losses. If livestock farms are affected by diseases such as foot-and-mouth disease, they suffer significant losses. This is because reducedproductivityinlivestocknotonlyaffectstheirproductionbutalsoentails substantial costs for vaccines and treatments. Therefore, there is a need to explore how to effectively prevent diseases, focusing on common diseases in cattle such as subclinical mastitis and mastitis, and alleviate the burden on farms economically and environmentally. This study aims to investigate the production of bacterial growth-inhibiting straw bedding using substances such as illite and charcoal to contribute to disease prevention.

Whose feather is that? A cross-views between a naturalist and a molecular biologist

Identifyingthespeciesorsexofabirdbasedonafeatherfoundinnatureisoftenchallenging,evenwith the help of reference books. However, determining the presence of a rare species in a habitat using an indirectpresenceindicator,suchasafeather,canhelpinimplementingspecificmeasuresforpreserving the species. The aim of this study is to investigate whether DNAgenotyping is better than specialized books when identifying bird feathers. Toanswerthisquestion,Icollectedfeathersinthewildand,withthehelpoftwobooks,triedtoidentify theirspeciesandsex.Then,assistedbyDrGwenaëlJacob(UNIFR),Iisolatedtwogenesinnineselected feathers. The investigated genes were the CHD gene for sexing and the COI gene for species identification.Todothis,theDNAwasfirstextractedfromthefeathers,purified,andamplifiedbyPCR. Subsequently,anelectrophoresis wasperformedtosexthe samples andcheckthatthe PCRamplification hadworkedproperly.Finally,thesamplesweresequencedbytheMicrosynthlaboratory(St-Gall),and the obtained sequences were entered into the NCBI database. Acomparisonoftheresultsobtainedwitheachofthetwodifferentmethodsshowsthattheidentification with specialized books was fairly successful. 56% of the species identification made with the books were indeed confirmed by genotyping. DNAanalysis provided a different result only for feather #16. However,33%ofgeneticidentificationfailed,eitherduetogeneticmaterialqualityorlaboratoryerrors. Asitwaspossibletoidentifythesexofonlyonesample(feather#14)withthebooks,itwasnotpossible tomakeatruecomparisonofthetwoapproaches.However,asgeneticsexingworkedwell(onefailure, feather #28), it can be inferred that genetic sexing is more effective than using books. This work demonstrated that DNAis not infallible and that sometimes books are equally effective in identifyingbirdspeciesfromafeather.However,insexingbird,DNAremainsmoreefficient.Thus,one can conclude that DNAgenotyping is not superior but rather complementary to specialized books for identifying bird feathers.

硬骨魚鰓上用以適應淡水酸化獨特的產氨與排氨機制

環境酸化為地球面臨的危機之一。面對酸逆境時,產氨及排氨為脊椎動物保守的適應策略,而本研究致力於探討脊椎動物之一的斑馬魚 (Danio rario) 在面對酸逆境時適應的特殊機制。首先,斑馬魚在pH值4.0環境下酸處理6小時後,水體及血液中氨濃度顯著上升。透過qRT-PCR,負責產氨的麩醯胺酸酶 (GLS, gls) 基因在鰓、肝、肌肉、腎中皆被誘發,顯示他們皆貢獻於排氨的過程。比較不同器官發現,鰓最早在6小時便啟動 gls基因,可知鰓除了負責魚類的排氨,也是面對急性酸逆境時最初的產氨器官。在斑馬魚的鰓上,我們也發現了硬骨魚特有的富含GLS的細胞 (GLS細胞),再次應證了硬骨魚面對酸逆境時,鰓上獨特的適應機制。本研究為氣候變遷議題提供了非常有價值及參考性的資訊,也協助預測未來持續環境酸化下硬骨魚類的未來。

Non-invasive study of the electrical activity of the brain of various chordate animals

In clinical practice, EEG is used to diagnose a number of neurological diseases and to diagnose epilepsy. But at present, the question of the nature of EEG has not been completely resolved and is of great scientific interest. There have been no studies at all on the non-invasive study of the electrical activity of the brain of the shark superorder, which belongs to the class of cartilaginous fish. By studying the electrical activity of the brain of various gnathostomes, it is possible to obtain an answer to the question of the emergence of rhythms from the point of view of phylogenesis and evolution, and by comparing their EEG with the human EEG, one can identify similar patterns that help in the study of reactions to various influences. During the work, for the first time, EEG indicators of spotted cat sharks, ECG, heart rate and respiratory rate of cat sharks and toads were obtained. In the future, it is planned to assemble a smaller neuroheadset for non-invasive studies of the electrical activity of the brain of small animals (sharks, toads, monitor lizards). This data can be used for evolutionary and medical research. *No animals were harmed during or after the experiments.