創傷式授精
![A female bed bug is held upside-down by a male bed bug, as he traumatically inseminates her abdomen.](http://upload.wikimedia.org/wikipedia/commons/thumb/6/63/Traumatic_insemination_1_edit1.jpg/220px-Traumatic_insemination_1_edit1.jpg)
創傷式授精(Traumatic insemination)是部分無脊椎動物的交配方式,即雄性用交接器刺入雌性的腹部,將精子注入腹腔(血腔)中。[1]精子通過雌性的血淋巴散播到卵巢中,使其懷孕。雌性癒合前身體會變得削弱、易於感染,健康受到損害。由於向血腔注入了精子和精液,其亦會產生免疫反應。[2]
臭蟲科昆蟲都使用此種授精方式,並為此演化出了受精儲精器。有人提出,受精儲精器可以減小創傷式授精對雌性的直接傷害。然而,統計學實驗沒有發現證實此假說的確鑿證據;防菌是更合理的解釋。
許多無脊椎動物物種都趨同演化出創傷式授精的方式,對溫帶臭蟲(Cimex lectularius)的研究是最全面的。[1][3]創傷式授精並不只限於同種動物的異性間,也可在異種和同性的動物間觀察到進行此種交配。
機制
[編輯]![A microscopic image of the spiny penis of a bean weevil, as seen from behind the beetle](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Callosobruchus_analis_penis.jpg/220px-Callosobruchus_analis_penis.jpg)
在包括人類的複雜生命系統中,血液和淋巴是分別在循環系統和淋巴系統中循環的,被毛細管、靜脈、動脈和淋巴結隔開。這稱為閉式循環系統。而昆蟲擁有開式循環系統,其血液和淋巴的循環沒有被隔開,它們合在一起以血淋巴的形式循環,器官也沐浴在其中,獲得氧氣和營養。[4]
在創傷式授精後,精子會隨着血淋巴流入雌性的卵巢,令其懷孕。不同的生物的具體機制有所不同。射精前,部分昆蟲的雄性會把自己的生殖器(半側體)刺進雌性的生殖道頂端,將雌性的交配囊壁刺穿;其他昆蟲的雄性會把雌性的外體壁刺穿。如果精子的到達卵巢並使卵子受精就算成功。[1]
不同物種的雌性對創傷式授精的反應也不同。包括臭蟲在內的物種會接受[5],而有些會抵抗並且試圖逃脫[6]。因為有證據表明,昆蟲沒有痛覺,所以這種抗拒應該不是出於疼痛。[7]
研究表明,雌性多數後代的父親是最後一個進行創傷式授精的雄性[8]。
演化適應
[編輯]![The vagina of a Richardson's ground squirrel, a mating plug fills the vaginal opening, blocking it.](http://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Mating_plug.jpg/220px-Mating_plug.jpg)
有多個可創傷式授精的演化論解釋。一種是,創傷式授精是對生育塞的適應性變化。很多物種使用生育塞的繁殖機制,雄性在交配後,會用粘液封上雌性的生殖道。[9]創傷式授精允許後來的雄性繞過雌性封上的生殖道,直接向循環系統注射精子。也有人認為,創傷式授精可令雄性避開求偶時雌性的抗拒[1],縮短求偶時間,允許雄性在短時間內授精給多個雌性[10]。也有可能是因為,創傷式的精子離卵巢更近,在精子競爭中取得勝利。
這種奇特的授精機制,可能是雄性臭蟲在為把精子與放得離卵巢更近的競爭演化形成的。一些昆蟲的雄性演化出了更長的交接器,進入陰道時可越過雌性的儲精袋,使精子更接近卵巢。少部分雄性,比如昆蟲,則殊途同歸地演化出了創傷式授精的方式,最終,這種奇特的步驟成為了這類昆蟲的標準生殖方式。[11]
最近發現,植食蝽屬盲蝽科(Coridromius)下的物種也採用創傷式授精。此種臭蟲中,雄性的插入器由陽莖和左半側體結合構成;雌性插入區的副生殖器產生變性,形成凹槽和凹入的交配管,以引導雄性半側體。盲蝽科也演化出創傷式授精,顯示第三種蝽此類交配方式的獨立出現。[12] 事實上,Coridromiini族的物種都採取這種交配的方式[13]。
健康影響
[編輯]儘管創傷式授精對雄性生殖有利,但令雌性付出了代價:減短的壽命和降低的繁殖產出。代價具體有:
- 傷口需要恢復;
- 失血;
- 上升的傷口感染機會;
- 對直接注入血液的精液或附屬腺液體的排斥。[1]
雄性臭蟲的交接器攜帶有5種對人類致病的微生物,雌性臭蟲的外骨骼上有9種,其中包括產黃青黴菌、腐生葡萄球菌、嗜麥芽寡養單胞菌、地衣芽孢桿菌和藤黃微球菌。血平板測試表明,部分病原菌可在其體內存活,這可能是此種授精方式會使臭蟲短命的原因。[14]
為了癒合傷口,雌性需要耗費更多能量,那麼進行其他活動的能量就減少了。傷口如果帶來感染,壽命也會縮短。注射到血淋巴的精子和精液成為雌性的抗原,引起免疫反應。
實驗室中,密集飼養的臭蟲易於從雌性開始滅絕。[15]這是因為,此種情況下,交配過於頻繁,對雌性的健康十分不利[1],於是25%的雌性在完整受精前就已死亡[16]。
臭蟲的演化適應
[編輯]![腹側向上放置的床蚤,其腹部右側(相片左側)有創傷式受精的傷口](http://upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Traumatic_insemination_2.jpg/100px-Traumatic_insemination_2.jpg)
創傷式授精產生對雌性有害的影響,於是她們在刺穿的地方演化出了一對專門的繁殖器官(paragenitalia),稱為外部儲精器和中間儲精器(合稱為受精儲精器),裡面的精子可以遷移到卵巢中。[2][17]所有的臭蟲都通過上述方式生殖。雖然生殖道依舊完整[18],但只用於產下受精卵[3]。
外部儲精器位於腹部,是一個脹起的部分,通常是折起的,裡面是血細胞。多種臭蟲的外部儲精器都是可見的,雄性會用半側體對準它。沒有可見外部儲精器的物種中,雄性會在體表的大範圍上釘入。[18]
在此方面,雄性「服從」雌性支配的具體原因還不清楚,尤其當考慮到P. cavernis似乎可以在外部儲精器之外刺入。一種可能是,在外部儲精器之外刺入會降低雌性的繁殖力,這樣她為雄性生下的後代也會減少。外部儲精器是對雌雄都有利的交配嚮導,讓雄性釘入雌性腹部的有限區域。[18]
中間儲精器位於外部儲精器裡面,是一個囊泡,精子會注入其中。在部分物種的中間儲精器會直接連接到卵巢,這樣精子和精液就不會進入血淋巴,也就不會引起免疫反應了。(不同種族的臭蟲的儲精器有所不同。)[1]通常,只有雌性才有儲精器,而Afrocimex屬的雄性也擁有外部儲精器。[1]儲精器里的精子大約會保留4小時;2天後會全部消失。[3]
雄性臭蟲的交接器上演化出了化學感受器,刺中一個雌性後,他可以「嘗出」那個雌性受否剛剛交配過,他會與剛剛交配過的雌性交配更短的時間,注入的液體也更少。[19]
動物界的使用
[編輯]創傷式授精是異翅亞目(如臭蟲)最廣泛採用的授精方式,也在其他無脊椎動物類群中使用。其中包括:
- 蟯蟲(線蟲) —— 在蟯蟲的屬Auchenacantha、Citellina、Passalurus中發現創傷式授精,此外還可能包括及Austroxyris。[1][20][21]
- 棘頭動物門(寄生,棘頭蟲) —— Pomphorhynchus bulbocolli兩側交配栓的存在說明,這些動物存在創傷式授精的方式。由於這些寄生蟲釘在宿主腸後就無法動彈,可能由於行動的不便而演化出這種授精方式。[1][22]
- 輪形動物門(輪蟲) —— 臂尾輪屬中,雄性會把合胞體壁(相當於皮膚)刺入並注入精子;雄性卜氏晶囊輪蟲會分泌一種酶,將雌性體壁破出一個洞,注入精子。[23][24]
- 渦蟲綱(自由生活的扁蟲) —— 雌雄間性的扁蟲會通過「交接器擊劍」進行交配,試圖使自己的交接器插入皮膚,注入精子。「輸」的一方被授精,且進行繁殖,它們的代價是由於繁殖造成的能量損失。對扁蟲Pseudoceros bifurcus的一項研究發現:大部分的受精都是單系的,即使再次被交接器插入,其交配時間也會小於第一個。[25][26]
- 腹足類動物:蝸牛[1]
- 捻翅目(捻翅寄生蟲) —— Xenos vesparum既可通過非生殖道管道,也可通過血腔射入精子實現受精。[27]
- Drosophila (果蠅)—— 精液會通過體壁注入生殖道,而不是腹部。[28]
- 後鰓目 (海蛞蝓) —— 少量多次向雌性背表面注入精子,實現標準的生殖器授精,但會被同步循環運動干擾。[29]
- Harpactea(蜘蛛) – 蜘蛛Harpactea sadistica的雄性會將交接器插入雌性身體的凹槽處,直接向子宮注射精子。[30]
同性間的創傷式授精
[編輯]創傷式授精不只適用於雌雄夫妻。在花蝽Xylocoris maculipennis種[9]和臭蟲Afrocimex屬的昆蟲中,也觀察到了雄性間進行創傷式授精的現象。[1]
Afrocimex屬的雌雄昆蟲都發展出了外部儲精器(只有雌性有中間儲精器),但有所不同。卡拉永在1966年發現,雄性Afrocimex臭蟲確實有同性創傷式授精行為。他發現,雄性外部儲精器顯示了交配痕跡,外來精子在身體中散布,但沒有在生殖器內或周圍找到,因此不可能是在與雌性創傷式授精時進入的,而是發生了同性交配。同性創傷式授精的成本與收益仍然未知。[1]
謝菲爾德大學的克勞斯·萊因哈特等人觀察到了擁有不同形態受精儲精器的兩種Afrocimex constrictus。這種昆蟲中,雄性和雌性都被進行創傷式授精。他們發現,雌性通過模仿成雄性,降低被創傷式授精的頻率。擁有雄性型受精儲精器的雌性比雌性型的被進行創傷式授精的頻率要小。[31]
Xylocoris maculipennis的雄性(受)在被其他雄性(攻)創傷式授精後,攻的精子會移動到受的睾丸中。(受會消化大部分的精子和精液,相當於享受了一頓營養豐富的美餐。)雖然沒有證據,但是有人猜測,受給雌性授精時,也會注入攻的精子。[32][33]
不同物種間的創傷式授精
[編輯]不同物種間的創傷式受有時會引起致命的免疫反應。被雄性熱帶臭蟲射精的溫帶臭蟲會在刺透部位腫大,壽命也會縮短。有些情況下,免疫反應會很強,甚至致命。在被雄性Hesperocimex cochimiensis創傷式授精後,雌性Hesperocimex sonorensis先會膨脹,之後變黑,24至48小時內便會死亡。[1]
類似的交配方式
[編輯]動物界中,創傷式授精並不是強迫性交的唯一方式。
研究顯示,龍虱的Acilius屬的雌雄間沒有求愛系統,而擁有一個「強姦」系統。雌性不會默默接受強姦,演化出了反抗武器。雄性會將雌性悶在水裡直至精疲力竭,最長6小時(為防止其與其他雄性交配),其中只偶爾允許其到水面呼吸一下。為防被雄性抓住,雌性的身體演化出了多種形狀。雌性為趕走雄性,瘋狂在水中游泳就是他們的「前戲」。[34]
在一些種類的鴨子中,也可觀測到多種「強姦行為」。藍翅鴨中,成對的雄性會在繁殖期的任何時間進行強姦。對成對的雄性的益處包括,成功繁殖、從領地中趕走入侵者。[35]
寬吻海豚屬的單身獸群會聚集在一頭雌性旁邊,強迫其進行性交。如果不從,就發出言語或身體威脅。[36][37]
昆蟲中,雄性水黽如果無法刺入生殖盾,就會吸引天敵到雌性周圍,直至交配。[38]
參考資料
[編輯]- ^ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 Arnqvist, Göran; Rowe, Locke. Sexual Conflict (Monographs in Behavior and Ecology). Princeton, NJ: Princeton University Press. 2005-07-05: 87–91. ISBN 978-0-691-12218-2.
- ^ 2.0 2.1 Reinhardt, K.; Naylor R.; Siva-Jothy, M. T. Reducing a cost of traumatic insemination: female bedbugs evolve a unique organ. Proceedings of the Royal Society B. 2003-11-22, 270 (1531): 2371–2375. PMC 1691512
. PMID 14667353. doi:10.1098/rspb.2003.2515.
- ^ 3.0 3.1 3.2 Carayon, J. Paragenital system. Monograph of Cimicidae (Hemiptera, Heteroptera). College Park, MD: Entomological Society of America. 1966: 81–166. ASIN B0000EGQ6L. ISBN 978-0-9776209-2-0.
- ^ Ruck, B.N.; Villares, G.J.; Welch, C.M.; Facey, D.E. Circulatory System. Saint Michael's College. [2009-08-19]. (原始內容存檔於2009-06-19).
- ^ Arnqvist, citing A.D. Stutt, Reproductive Strategies and Sexual Conflict in the Bed Bug. PhD thesis. University of Sheffield, England.
- ^ Arnqvist 89, citing personal observations and Monograph of Cimicidae
- ^ Smith, Jane A. A Question of Pain in Invertebrates. ILAR Journal. 1991, 33 (1–2) [2009-04-07]. (原始內容存檔於2009-04-18).
In the majority of examples of invertebrate nociception noted above, there seems to be little, if any, evidence that the animals' responses persist in anything akin to the manner described for mammals. As Eisemann et al. (1984) have described in a review of the 'biological evidence' concerning pain in insects, 'No example is known to us of an insect showing protective behavior towards injured parts, such as by limping after leg injury or declining to feed or mate because of general abdominal injuries. On the contrary, our experience has been that insects will continue with normal activities even after severe injury or removal of body parts.'... Certainly, on the limited amount of evidence presented here, it seems very difficult to imagine that insects and the other simpler invertebrates mentioned above can 'suffer' pain in anything like the vertebrate sense. Nevertheless, the issue certainly is not closed, and further questions should be asked.
- ^ Stutt AD, Siva-Jothy MT. Traumatic insemination and sexual conflict in the bed bug Cimex lectularius. Proceedings of the National Academy of Sciences, U.S.A. 2001-05-08, 98 (10): 5683–87 [2009-04-09]. PMC 33273
. PMID 11331783. doi:10.1073/pnas.101440698.
- ^ 9.0 9.1 Quammen, David. The Flight of the Iguana: A Sidelong View of Science and Nature. Simon & Schuster. 1998-02-16: 29–30 [1988]. ISBN 978-0-684-83626-3.
- ^ Trowbridge, C. D. Hypodermic insemination, oviposition, and embryonic development of a pool-dwelling ascoglossan (=sacoglossan) opisthobranch: Ercolania felina (Hutton, 1882) on New Zealand shores. The Veliger. 1995, 38: 203–211.
- ^ Waldbauer, Gilbert. Insects through the seasons. Harvard University Press. 1998-02-11: 63. ISBN 978-0-674-45489-7.
- ^ Tatarnic, Nikolai J; Gerasimos Cassis; Dieter F Hochuli. Traumatic insemination in the plant bug genus Coridromius Signoret (Heteroptera: Miridae). Biol Lett. (The Royal Society). 2006-03-22, 2 (1): 58–61. PMC 1617170
. PMID 17148326. doi:10.1098/rsbl.2005.0394.
- ^ Kim, Jung-gon; Jung, Sung-Hoon. A new record of the tribe Coridromiini (Hemiptera: Heteroptera: Miridae: Orthotylinae) from the Korean Peninsula. Journal of Asia-Pacific Biodiversity. 2016-06-01, 9 (2): 253–255 [2018-10-18]. doi:10.1016/j.japb.2016.02.002. (原始內容存檔於2021-05-05) (英語).
- ^ Reinhardt, Klaus; Naylor, Richard A., Siva-Jothy, Michael T. Potential sexual transmission of environmental microbes in a traumatically inseminating insect. Ecological Entomology. 2005-09-21, 30 (5): 607–611. doi:10.1111/j.0307-6946.2005.00730.x.
- ^ Arnqvist, citing Monograph of Cimicidae
- ^ University of Sheffield Department of Animal & Plant Sciences Research Projects. [2004-09-19]. (原始內容存檔於1996-01-01).
For this purpose we are studying the traumatic insemination of bed bugs. The natural mating rate of bed bugs is such that females suffer 25% higher mortality than is necessary for full fertilization. This is apparently not outweighed by 25% benefits to the offspring. So far, we have identified that a unique organ, the spermalege has possibly evolved to mediate pathogenic microbes transmitted during copulation. By contrast, the amount of wounding and wound repair in response to piercing is not mediated by the spermalege, nor are the action of seminal fluids. We are presently testing whether costs to activate the immune system, or costs to maintain sperm alive contribute to the increase female mortality.
- ^ Morrow, Edward H.; Arnqvist, Göran. Costly traumatic insemination and a female counter-adaptation in bed bugs. Proceedings of the Royal Society B. 2003-11-22, 270 (1531): 2377–2381. PMC 1691516
. PMID 14667354. doi:10.1098/rspb.2003.2514.
- ^ 18.0 18.1 18.2 Siva-Jothy MT. Trauma, disease and collateral damage: conflict in cimicids. Philosophical Transactions of the Royal Society B. 2006-02-28, 361 (1466): 269–75. PMC 1569606
. PMID 16612886. doi:10.1098/rstb.2005.1789.
- ^ Siva-Jothy MT and Alistair D. Stutt. A matter of taste: direct detection of female mating status in the bedbug. Proceedings of the Royal Society B. March 2003, 270 (1515): 649–652. PMC 1691276
. PMID 12769466. doi:10.1098/rspb.2002.2260.
- ^ Anderson, Roy Clayton. Nematode parasites of vertebrates. CABI. 2000: 233. ISBN 0-85199-421-0.
- ^ Hugot, JP. Traumatic insemination and tubular egg receptacle in the pinworm [Passalurus ambigus] parasite of the common domestic rabbit. Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences. Serie 3. Sciences de la Vie (France). 1982-04-19, 294 (14): 707–10.
- ^ Doyle, Lester R.; Larry N. Gleason. Suckers and Other Bursal Structures of Pomphorhynchus bulbocolli and Acanthocephalus dirus (Acanthocephala). The Journal of Parasitology (The American Society of Parasitologists). June 1991, 77 (3): 437–40. JSTOR 3283132. PMID 2040955. doi:10.2307/3283132.
- ^ Wallace, R. L. Rotifera. Knobil, Ernst; Neill, Jimmy D (編). Encyclopedia of Reproduction. Boston: Academic Press. 1998: 290–301. ISBN 0-12-227020-7.
- ^ Obst, Matthias; Funch, Peter. Dwarf male of symbion pandora (cycliophora). Journal of Morphology. 2003-01-06, 255 (3): 261–78. PMID 12520546. doi:10.1002/jmor.10040.
- ^ Michiels, N. K.; Newman, L. J. Sex and violence in hermaphrodites. Nature. 1998-02-12, 391 (647): 647–8. ISSN 0028-0836. PMID 859632. doi:10.1038/35527.
- ^ Milius, S. Hermaphrodites duel for manhood. Science News Online. [2009-08-19]. (原始內容存檔於2008-03-26).
- ^ Beani L, Giusti F, Mercati D, Lupetti P, Paccagnini E, Turillazzi S, Dallai R. Mating of Xenos vesparum (Rossi) (Strepsiptera, Insecta) revisited. Journal of Morphology. 2005-07-26, 265 (3): 291–303. PMID 16047336. doi:10.1002/jmor.10359.
- ^ Kamimura, Yoshitaka. Twin intromittent organs of Drosophila for traumatic insemination. Biol Lett. (The Royal Society). 2007-08-22, 3 (4): 401–404. PMC 2391172
. PMID 17519186. doi:10.1098/rsbl.2007.0192.
- ^ Schmitt V, Anthes N, Michiels NK. Mating behaviour in the sea slug Elysia timida (Opisthobranchia, Sacoglossa): hypodermic injection, sperm transfer and balanced reciprocity. Frontiers in Zoology. 2007, 4: 17 [2009-04-09]. PMC 1934903
. PMID 17610714. doi:10.1186/1742-9994-4-17.[失效連結]
- ^ Řezáč, Milan. The spider Harpactea sadistica: co-evolution of traumatic insemination and complex female genital morphology in spiders. Proceedings of the Royal Society B. 2009-04-29, 276 (1668): 2697–701 [2009-05-09]. PMC 2839943
. PMID 19403531. doi:10.1098/rspb.2009.0104. (原始內容存檔於2013-11-09). Abstract at link
- ^ Reinhardt, Klaus; Ewan Harney, Richard Naylor, Stanislav Gorb, Michael T. Siva‐Jothy. Female‐Limited Polymorphism in the Copulatory Organ of a Traumatically Inseminating Insect. American Naturalist. 2007, 170 (6): 931–35 [2014-07-06]. PMID 18171174. doi:10.1086/522844. (原始內容存檔於2021-05-05).
- ^ Krebs, John R.; Davies, Nicholas B. An Introduction to Behavioural Ecology. Wiley-Blackwell. 1993: 186. ISBN 0-632-03546-5 請檢查
|isbn=
值 (幫助). , citing Carayon, J. Insemination traumatique heterosexuelle et homosexuelle chez Xylocoris maculipennis (Hem., Anthocoridae). Comptes Rendus de l'Academie des Sciences (France). 1974, 278: 2803–06. - ^ Abele, Lawrence G.; Sandra Gilchrist. Homosexual Rape and Sexual Selection In Acanthocephalan Worms. Science. 1977, 197 (4298): 81–83. PMID 867055. doi:10.1126/science.867055.
- ^ Smith, Lewis. Not tonight, not ever. I've got a headache. Don't come near me. The Times (London). 2007-06-25: 25 [2009-04-03].
- ^ Bailey, Robert O.; Seymour, Norman R.; Stewart, Gary R. Rape Behavior in Blue-Winged Teal. The Auk. January 1978, 95 (1): 188–90.
- ^ Angier, Natalie. Dolphin Courtship: Brutal, Cunning and Complex. The New York Times (New York City). 1992-02-18: C1 [2009-04-03]. (原始內容存檔於2009-04-12).
- ^ Connor, Richard C.; F. Andrew, Rachel A. Smolker, Janet Mann. Patterns of Female Attractiveness in Indian Ocean Bottlenose Dolphins. Behaviour. February 1996, 133 (1/2): 37–69. doi:10.1163/156853996X00026.
- ^ Han, Chang S.; Jablonski, Piotr G. Male water striders attract predators to intimidate females into copulation. Nature Communications. August 2010, 1 (52): 1. PMC 2964456
. PMID 20975717. doi:10.1038/ncomms1051.