Melanizm
Bu maqola avtomat tarjima qilingan yoki mashina tarjimasi tayinli oʻzgartirishsiz chop etilgani eʼtirof etilmoqda. Tarjimani tekshirib chiqish hamda maqoladagi mazmuniy va uslubiy xatolarini tuzatish kerak. Siz maqolani tuzatishga koʻmaklashishingiz mumkin. (Shuningdek, tarjima boʻyicha tavsiyalar bilan tanishib chiqishingiz mumkin.) DIQQAT! BU OGOHLANTIRISHNI OʻZBOSHIMCHALIK BILAN OLIB TASHLAMANG! Maqolaning originali koʻrsatilinmagan. |
![](http://178.128.105.246/content-http-upload.wikimedia.org/wikipedia/commons/thumb/3/31/Melsquir.jpg/220px-Melsquir.jpg)
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Melanizm - kasalligi bu organizmdagi melaninning pigmentining tug'ma (ortiqcha) oshib ketishi natijasida qora pigment paydo bo'ladi.
Psevdomelanizm kasalligi shuningdek, ko'p miqdorlilik deb ataladi, ya"ni pigmentatsiyalanishning yana bir varianti hisoblanib, qora dog'lar yoki kengaygan chiziqlarning tanada borligi bilan ko'zga tashlanadi, bu hayvon tanasining katta qismini qoplaydi va uni melanistik ko'rinishga olib keladi[2].
Melanoz kasalligi ko'pincha hayvonlarda pigmentli o'smalarni keltirib chiqaradigan malign xarakterga ega bo'lgan qora morbid moddasining organizmda ko'payib ketishi natijasida xosil bo'ladigan genetik holatga aytiladi. Shu sababli hayvonlarda quyuq pigmentatsiyaga ega bo'lgan genetik mutatsiyaga sabab bog'liq bo'lgan holati deb hisoblanadi.
Moslashuv
[tahrir | manbasini tahrirlash]![](http://178.128.105.246/content-http-upload.wikimedia.org/wikipedia/commons/thumb/c/c0/Hugorme.jpg/220px-Hugorme.jpg)
Melanizm bilan hastalanish adaptatsiya bilan bog'liq deb ataladi. Ko'pincha qorong'i muhitida omon qolish va ko'payish uchun mosroq bo'lib qoladilar melanizm bo'lgan organizmlar, chunki ular yaxshiroq nigoblashgan bo'ladi atrof-mujit sharoitiga. Bu ba'zi turlarni, yirtqichlar uchun deyarli ko'rinmas tusga keltiradi, boshqa hayvonlarda esa, masalan, qoplon, tungda ov qilish paytida maskirovkadan ozuqa ovlash uchun afzallik sifatida foydalanadilar [3]. Odatda, moslashuvchan (adaptiv) melanizm irsiydir : to'liq yoki chala to'liq fenotipda ifodalangan dominant allel melaninning ortiqcha miqdori natijasida vujudga keladi.
Moslashuvchan melanizm turli hayvonlarda, jumladan, olmaxonlar, ko'plab mushuklar va bo'risimonlarlar va marjon ilonlarida uchrashishi aniqlangan. Adaptiv melanizm polimorfozlarning paydo bo'lishiga olib kelishi mumkin, muhim misollardan biri, Buyuk Britaniyada evolyutsiyaning rivojlanish tarixi tabiiy tanlanish tamoyillarini o'rgatish maqsadida klassik o'quv vositasi sifatida taqdim etilgan[4].
Iqtisotda melanizmning ta'siri
[tahrir | manbasini tahrirlash]Sanoatlashgan melaniz iqtisodiy ifloslanishiga o'z ta'sirini ko'rsatib kelmoqda,misol uchun milanizmlashgan qalampirli kuya kapalagi, Biston betularia kabi hasharotlar evolyutsion ta'sir ko'rsatmoqda. To'q rangli pigmentli organizmlar tabiiy tanlanish maxsuli hisoblanadi, chunki ular ifloslangan muhitga nisbatan yaxshiroq niqoblashgan . Keyinchalik ifloslanish darajasi kamaytirilganda, ularda nisbatan oddiy shaklga ega bo'lishdi va melanizm kamroq uchray boshladi[5] [6] [7] [8] [9] [10]. Boshqa tasvirlashlar ham bor, masalan, melanin pigmenti immunitetni himoya qilish funktsiyasini kuchaytiradi [11], yoki quyuq rangda issiqlikni saqlashdaafzallikga ega bo'lish[12] [13] [14].
Mushuklarda
[tahrir | manbasini tahrirlash]![](http://178.128.105.246/content-http-upload.wikimedia.org/wikipedia/commons/thumb/6/67/Melanism_in_Panthera_Onca.jpg/220px-Melanism_in_Panthera_Onca.jpg)
Mushuksimonlarning melanistiklik holati 37 ta vakildauchraydigan turidan 11 tasida keng tarqalgan polimorfizm sifatida yuzaga keladi va ba'zi hollarda populyatsiyada eng yuqori chastotasiga etishi mumkin, ammo hech qachon to'liq fiksatsiyalashmaydi bit tur ichida. Qora pantera, melanistik leopard, Malayaning ekvatorial yomg'ir o'rmonida va Keniya tog'i kabi ba'zi Afrika tog'lari yonbag'irlaridagi tropik yomg'ir o'rmonlarida keng tarqalgan. Serval kabi mushuksimon yirtqich hayvonlar Sharqiy Afrikaning ayrim hududlarida ham melanistik shakllarga ega ekanligi aniqlangan. Yaguardlarning rangi quyuq jigarrang va kulrangdan och qizg'ish ranggacha o'zgaradi. Yaguarning melanik shakllari Janubiy Amerikaning ayrim qismlarida keng tarqalgan [15]. 1938 va 1940- yillarda Floridaning subtropik qismida ikkita melanistik bobcat (yovoyi mushuk) tiriklayin tuzoqqa tushgani aniqlangan [16].
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![Melanistic eastern gray squirrel](http://178.128.105.246/content-http-upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Melanistic_eastern_gray_squirrel_2.jpg/220px-Melanistic_eastern_gray_squirrel_2.jpg)
2003-yilda yaguarlarda melanizmning nasldan-naslga o'tishi dominant usuli 116ta individual tutqun saqlanib nasl- nasabida fenotiplarining transformatsiya bo'lishi orqali o'tishi aniqlandi. 24 ta asosiy juftlikni yo'q qilish yaguarundidagi melanizm uchun to'liq bo'lmagan dominant allelni keltirib chiqaradi. Aguti geni kodlash hududida agouti signalizatsiya peptidining ketma-ketligi qora uy mushuklarida 2 tayanch juftlikni yo'q bo'lib ketganligi aniqladi. Bu variantlar Geoffroy mushuki, oncilla, pampa mushuki va Osiyo oltin mushukining melanistik shaxslarida yo'q edi, bu melanizm mushuklar oilasida kamida to'rt marta mustaqil ravishda paydo bo'lganligini ko'rsatadi [17].
Leopardlardagi melanizm dog'li shaklga nisbatan Mendel, monogen retsessiv xususiyat sifatida nasldan naslga o'tadi. Qora hayvonlarning juftligi boshqa mumkin bo'lgan juftliklarga qaraganda sezilarli darajada kichikroq hajmiga ega[18]. 1996-yil yanvaridan 2009-yil martigacha Malay yarim orolidagi 16 ta joyda Hindi-xitoy leopardlari 1000 dan ortiq tungi tuzoq namunalarini olish jarayonida suratga olindi. Melanistik leopardlarning 445 ta fotosuratidan 410 tasi Kra Isthmus janubida olingan, bu erda melanistik bo'lmagan morf hech qachon suratga olinmagan. Ushbu ma'lumotlar mintaqadagi qora allelning yaqin fiksatsiyasi borligini ko'rsatadi. Ushbu retsessiv allelni faqat genetik ko'chish tufayli amalga oshishi uchun yetarli bo'lgan vaqt taxminan 1100 yildan 100 000 yilgacha bo'lganligi olimlar tomonidan anilangan[19]. Qoplonlarda uchraydigan melanizm pistirma qilib ovlash uchun evalutsion tanlanish natijasida vujudga kelgani va bu esa ular uchun afzallik bilan bo'liq asosiy sabab deb taxmin qilingan[20] Boshqa nazariyalarga ko'ra, mushuklarda melanizm uchun genlar virusli infektsiyalarga qarshilik ko'rsatishi yoki baland tog'larga moslashishi mumkin deb hisoblanadi, chunki qora mo'yna issiqlik uchun ko'proq yorug'likni to'playdi. [21].
Qushlarda
[tahrir | manbasini tahrirlash]![](http://178.128.105.246/content-http-upload.wikimedia.org/wikipedia/commons/thumb/1/10/Poule_Soie_gris_perle.jpg/220px-Poule_Soie_gris_perle.jpg)
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Silkie va Ayam Cemani tovuq zotlari odatda bu xususiyatni namoyon bo'ladii. Ayam Cemani - Indoneziyada paydo bo'lgan betakror va zamonaviy tovuq zoti hisoblanadi. Ular giperpigmentatsiyani (Fibromelanoz) keltirib chiqaradigan va nasldan naslga o'tadigan dominant genga ega bo'lib, tovuqni butunlay qora rangga aylantiradi; shu jumladan patlar, tumshug'i va ichki organlari ham.
Tadqiqotlar shuni ko'rsatdiki 2015-yil aprel oyida O'rta er dengizidagi Kipr orolida juda kam uchraydigan qora rangli flamingoda ham kuzatilgani aniqlangan[22].
Amfibiyalarda
[tahrir | manbasini tahrirlash]Alp salamandra (Salamandra atra)-bu turdagi kaltakesaksimonlarning butunlay tana rangi qora rangda bo'lgan bitta kichik turga mansub ( S. atra atra ) egadir[23]. Pigment melanin birikmasini ishlab chiqaradigan melanofor deb ataladigan o'ziga xos hujayradan tashkil topgan[24] [25].
Ushbu salamanderning yana to'rtta kichik turi mavjudligi aniqlangan [26] va ularning pegmentatsiyalanish darajalari ham turli xil bo'ladi[25] [27] [28]. Turkum ichidagi turlarda xar hil konsentratsiyalashgan yoki boshqalariga nisbatlarda sariq dog'lar mavjudigi aniqlangan. Ayrim kenja turlarning sariq dog'lariga hissa qo'shadigan pigment ishlab chiqaruvchi hujayralari bor va ksantoforlar deb ataladi [27]. Ko'rinib turibdiki, to'liq qora fenotiplar hech qachon bu ksantoforlarni rivojlantirmaydi[28]. Alp salamandrlari teridan toksin ishlab chiqaradi va to'liq melanistik, qora salamandrlar va dog'li birikma hosil qiladi[29].
DNK sini o'rganish bo'yicha olib borilgan tadqiqotlar shuni ko'rsatdiki, haqiqiy alp salamandrining fenotipi qora, ayrimlari sariq dog'lar bilan, ya'ni butunlay qora rang vaqt o'tishi bilan rivojlanib, ko'p avlodlarda nasldan naslga o'tishi aniqlangan [28].
Odamlarda
[tahrir | manbasini tahrirlash]Melanizm, ya'ni butunlay qora teriga olib keladigan mutatsiya hioblanadi, lekin odamlarda uchrashishi mumkin emasligi aniqlangan, shuning sababli oq tanli ikkita ota-onadan qora teriga ega bo'lgan bolaning tug'ilishi mumkin emas deb hisoblanadi. Melanin uchta dominant allel (AABBCC) bo'lib, oq tanlilarda qora tanlilar kabi ko'p bo'lmaydi. [30] Melanin teri pigmentatsiyasi darajasining asosiy omili hisoblanib, tanani zararli ultrabinafsha nurlanishidan himoya qiladi. Xuddi shu ultrabinafsha nurlanish terida D vitamini sintezi uchun zarur hisoblanadi, shuning uchun yorqin rangli teri - kamroq melanin - odamlarning ekvatorial hududlardan uzoqda bo'lgan tarixdan oldingi harakati bilan bog'liq moslashuvi deb hisoblanadi, va shu sababli, yuqori kengliklarda quyosh nuri kamroq ta'sir qiladi. Afrika, Janubiy Osiyo, Janubi-Sharqiy Osiyo va Avstraliyaning bir qismidan kelgan odamlarning terisi juda qora bo'lishi mumkin, ammo bu melanizm emas.
Manbalar
[tahrir | manbasini tahrirlash]- ↑ Morales, E.. The Guinea Pig : Healing, Food, and Ritual in the Andes. University of Arizona Press, 1995. ISBN 0-8165-1558-1.
- ↑ Osinga, N.; Hart, P.; van VoorstVaader, P. C. (2010). "Albinistic common seals (Phoca vitulina) and melanistic grey seals (Halichoerus grypus) rehabilitated in the Netherlands". Animal Biology 60 (3): 273−281. doi:10.1163/157075610x516493. https://semanticscholar.org/paper/8eaaadeb5203f4c27c8ecee433b934e4ab18618d.
- ↑ King, R.C., Stansfield, W.D., Mulligan, P.K. (2006). A Dictionary of Genetics, 7th ed., Oxford University Press
- ↑ Begon, M.. Ecology: From individuals to ecosystems, Fourth, Malden, Oxford: Wiley Publishing, 2006. ISBN 9781405151986.
- ↑ Majerus, M. E. (2009). Industrial melanism in the peppered moth, Biston betularia: an excellent teaching example of Darwinian evolution in action. Evolution: Education and Outreach, 2(1), 63-74.
- ↑ McIntyre, N. E. (2000). Ecology of urban arthropods: a review and a call to action. Annals of the Entomological Society of America, 93(4), 825-835.
- ↑ Cook, L. M., Saccheri, I. J., 2013. The peppered moth and industrial melanism: evolution of a natural selection case study. Journal of Heredity 110:207-12
- ↑ Grant, B. S., Wiseman L. L., 2002. Recent history of melanism in American peppered moths. Journal of Heredity 93:86-90.
- ↑ Brakefield, P. M., Liebert, T. G., 2000. Evolutionary dynamics of declining melanism in the peppered moth in the Netherlands. Proceedings of the Royal Society of London Biology 267:1953-1957.
- ↑ Grant, B. S., Cook, A. D., Clarke, C. A., & Owen, D. F. (1998). Geographic and temporal variation in the incidence of melanism in peppered moth populations in America and Britain. Journal of Heredity, 89(5), 465-471.
- ↑ Mikkola, K., & Rantala, M. J. (2010). Immune defence, a possible nonvisual selective factor behind the industrial melanism of moths (Lepidoptera). Biological Journal of the Linnean Society, 99(4), 831-838.
- ↑ Mikkola, K., Albrecht, A., 1988. The melanism of Adalia-bipunctata around the Gulf of Finland as an industrial phenomenon (Coleoptera, Coccinellidae). Annales Zoologici Fennici 25:177-85.
- ↑ Muggleton, J., Lonsdale, D., Benham, B. R., 1975. Melanism in Adalia-bipunctata L (ColCoccinellidae) and its relationship to atmospheric pollution. Journal of Applied Ecology 2:451-464.
- ↑ De Jong, P. W., Verhoog, M. D., Brakefield, P. M., 1992. Sperm competition and melanic polymorphism in the 2-spot ladybird, Adalla bipunctata (Coleoptera, Coccinellidae). Journal of Heredity 70:172-178.
- ↑ Searle, A. G. (1968) Comparative Genetics of Coat Colour in Mammals. Logos Press, London
- ↑ Ulmer, F. A. (1941) Melanism in the Felidae, with special reference to the Genus Lynx. Journal of Mammalogy 22 (3): 285–288.
- ↑ Eizirik, E.; Yuhki, N.; Johnson, W. E.; Menotti-Raymond, M.; Hannah, S. S.; O'Brien, S. J. (2003). "Molecular Genetics and Evolution of Melanism in the Cat Family". Current Biology 13 (5): 448–453. doi:10.1016/S0960-9822(03)00128-3. PMID 12620197.
- ↑ Robinson, R. (1970). "Inheritance of black form of the leopard Panthera pardus". Genetica 41 (1): 190–197. doi:10.1007/BF00958904. PMID 5480762. https://www.semanticscholar.org/paper/9d7a7784960828ece75161fb0c1ea106fa073d23.
- ↑ Kawanishi, K.; Sunquist, M. E.; Eizirik, E.; Lynam, A. J.; Ngoprasert, D.; Wan Shahruddin, W. N.; Rayan, D. M.; Sharma, D. S. K. et al. (2010). "Near fixation of melanism in leopards of the Malay Peninsula". Journal of Zoology 282 (3): 201–206. doi:10.1111/j.1469-7998.2010.00731.x.
- ↑ Majerus, M. E. N. (1998). Melanism: evolution in action. Oxford University Press, New York
- ↑ Seidensticker, J., Lumpkin, S. (2006). Smithsonian Q & A: the ultimate question and answer book. Cats. Collins, New York
- ↑ Krol, Charlotte. „Rare black flamingo spotted in Cyprus“. The Telegraph (2015-yil 9-aprel). 2015-yil 25-aprelda asl nusxadan arxivlangan. Qaraldi: 2015-yil 16-may.
- ↑ „Salamandre noire“. www.karch.ch. Qaraldi: 2022-yil 30-noyabr.
- ↑ Trevisan, Pierluigi; Pederzoli, Aurora; Barozzi, Giancarlo (October 1991). "Pigmentary System of the Adult Alpine Salamander Salamandra atra atra (Laur., 1768)" (en). Pigment Cell Research 4 (4): 151–157. doi:10.1111/j.1600-0749.1991.tb00432.x. ISSN 0893-5785. PMID 1816547. https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0749.1991.tb00432.x.
- ↑ 25,0 25,1 Pederzoli, Aurora; Trevisan, Pierluigi (March 1990). "Pigmentary System of the Adult Alpine Salamander Salamandra atra aurorae (Trevisan, 1982)" (en). Pigment Cell Research 3 (2): 80–89. doi:10.1111/j.1600-0749.1990.tb00326.x. ISSN 0893-5785. PMID 2385569. https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0749.1990.tb00326.x.
- ↑ Helfer, V.; Broquet, T.; Fumagalli, L. (2012-08-30). "Sex-specific estimates of dispersal show female philopatry and male dispersal in a promiscuous amphibian, the alpine salamander (Salamandra atra)". Molecular Ecology 21 (19): 4706–4720. doi:10.1111/j.1365-294x.2012.05742.x. ISSN 0962-1083. PMID 22934886. http://dx.doi.org/10.1111/j.1365-294x.2012.05742.x.
- ↑ 27,0 27,1 Burgon, James D.; Vieites, David R.; Jacobs, Arne; Weidt, Stefan K.; Gunter, Helen M.; Steinfartz, Sebastian; Burgess, Karl; Mable, Barbara K. et al. (April 2020). "Functional colour genes and signals of selection in colour‐polymorphic salamanders" (en). Molecular fEcology 29 (7): 1284–1299. doi:10.1111/mec.15411. ISSN 0962-1083. PMID 32159878.
- ↑ 28,0 28,1 28,2 Bonato, Lucio; Steinfartz, Sebastian (2005-01-01). "Evolution of the melanistic colour in the Alpine salamander Salamandra atra as revealed by a new subspecies from the Venetian Prealps". Italian Journal of Zoology 72 (3): 253–260. doi:10.1080/11250000509356680. ISSN 1125-0003. https://doi.org/10.1080/11250000509356680.
- ↑ Beukema, Wouter; Speybroeck, Jeroen; Velo-Antón, Guillermo (August 2016). "Salamandra". Current Biology 26 (15): R696–R697. doi:10.1016/j.cub.2016.03.045. ISSN 0960-9822. PMID 27505235.
- ↑ Scheneider, Patricia (2004). "the genetics and evolution of human color". ProQuest. https://www.proquest.com/openview/ce7e635324be8a0c452ca71eec1e9419/1?pq-origsite=gscholar&cbl=49226.