'YAN DIGO KAƊAN NA DNA, RAGA MAI TAURI NINKI 25

Ka haɗa ƙwayoyi masu tauri cikin abu mai laushi sai ya ƙara tauri, gwargwadon fili da suka mamaye. Ga ƙananan adadi, dokar tana ɗauke da sunan Einstein: ana ninka tauri da 1 + 5ϕ/2, inda ϕ shi ne rabon girman abin da ƙwayoyin suka cike. Idan sun cike kashi ɗaya cikin goma na girman, wannan ninki ne na 1.25 — ƙarin tauri na 25% a mafi yawa, ko da ƙwayoyin suna da tauri cikakke.

Sam Wilken, a Jami’ar Johannes Gutenberg ta Mainz, Omar Saleh, a Jami’ar California, Santa Barbara, da abokan aikinsu sun yi amfani da digon ruwa a maimakon haka. Da suka cike ƙasa da kashi ɗaya cikin goma na girman, sun samar da abu mai tauri kusan ninki 25 — kuma ana iya mayar da shi yadda yake.

Zare daga tsoka, taurari da aka yi da DNA

Tushen abin cuɗanya ce ta actin, wadda aka tace daga garin tsokar zomo. Ƙananan sassanta suna haɗuwa su zama zare masu tsawon micrometre 10 zuwa 30 da kaurin nanometre 7 kawai. Suna tsayayya da lanƙwasawa: tsawon dagewarsu (persistence length), ma’aunin wannan tauri, kusan micrometre 17 ne, kusa da tsawonsu na kansu. Idan suka cuɗanya, suna samar da raga mai laushi.

Digon an yi su ne da taurarin-nano (nanostars) na DNA, ƙwayoyi masu hannaye huɗu masu faɗin kusan nanometre 10. Hannayensu suna ƙarewa da gajerun igiyoyi “masu ɗanko” da ke manne wa juna. Ƙasa da zafin narkewa — 27 zuwa 31 °C ya danganta da haɗin — taurarin suna taruwa su zama digon ruwa mai kauri na DNA, waɗanda ke sake narkewa sama da shi. Wannan shi ne rabuwar ruwa da ruwa (liquid–liquid phase separation), kuma ana kiran irin waɗannan digo na ƙwayoyin halitta condensates. Actin da DNA ba sa manne wa juna.

Digo da ke girma a kewayen zare

Ƙungiyar ta bar actin ya haɗu a 37 °C, sannan ta sanyaya samfurin. Ba tare da actin ba, digon sun haɗu sun zama manyan ɗigo da suka nutse. Tare da actin, sun ci gaba da zama ’yan micrometre kaɗan a faɗi, a rataye ko’ina. Ɗaukar hoto da launuka biyu ya kawo abin mamaki: alamar actin ta kasance daidai ko’ina har a cikinsu. Digon sun samu ne a kewayen zaren maimakon tura su gefe, don haka actin yana ratsa kowanne daga cikinsu — fiye da awa 14; bayan kwana uku, actin ya fita daga yawancinsu.

Ragar ce kuma ke ƙayyade girman digon. Digo suna girma ta hanyar girgiza nan da can da haɗuwa; ragar tana riƙe kowanne kamar a kan sumbu (spring), don haka haɗuwa tana tsayawa da zarar babu maƙwabci a kusa. Yawan taurin raga, ƙanƙantar digon, kamar yadda samfurin lissafin marubutan ya yi hasashe — kuma girmansu ya fi zama iri ɗaya fiye da lokacin da babu actin.

A: ragar actin (kore) da taurarin-nano na DNA (ruwan shunayya) kafin da bayan sanyaya. B: tare da actin, ƙananan digo suna kasancewa a rataye ko’ina cikin samfurin. C: ba tare da actin ba, suna girma sosai kuma suna nutsewa (g tana nuna jan ƙasa (gravity)). D–E: alamar actin tana zama daidai, har a tsallaken digo. — Hoto na 1, Wilken et al. (2026), arXiv:2610.38504.

Auna tauri ta hanyar murɗawa

An auna tauri a cikin na’urar rheometer, wadda ke murɗa siririn layin samfuri a hankali gaba da baya tsakanin faranti biyu na gilashi. Lambobi biyu suna fitowa: modulus na sassauci G′ (elastic modulus), ɓangaren tsayayya da ke komawa kamar abu mai ƙarfi, da modulus na asara G″ (loss modulus), ɓangaren da ke ɓacewa kamar a cikin ruwa. Dukansu ana auna su da pascal, ma’aunin matsi — a nan, matsin da ake buƙata don murɗa samfurin ga kowane ma’aunin sauyin siffa.

Ninki ashirin da biyar, ba kashi ashirin da biyar ba

Ragar actin ita kaɗai, a 20 µM (micromolar, ma’aunin yawan sinadari), tana da modulus na sassauci na kusan pascal 1 idan tana da ɗumi, ninki biyu na haka idan tana da sanyi. Ƙara 38 µM na taurarin-nano, narkakku sama da zafin narkewa, ya ninka shi biyu. Sannan, yayin da digo suka samu ƙasa da kusan 31 °C, modulus ɗin ya yi tsalle kuma ya ci gaba da hawa: a jadawalin ƙungiyar, ya kai kusan pascal 100 a 10 °C.

Idan aka raba shi da modulus na haɗin iri ɗaya ba tare da digo ba, wannan yana ba da ninkin ƙarin tauri na kusan 25 a mafi ƙanƙantar zafi, tare da digon da suka cike kusan kashi 9% na girman kawai. A wannan rabo, dokar Einstein tana ba da damar ninki na 1.225 a mafi yawa. Kuma juya zafin baya da gaba ta tsallaken zafin narkewa yana sauya abin tsakanin laushi da tauri, sau da sau, cikin kusan minti 10 — lokacin da digo ke ɗauka don kaiwa girmansu na ƙarshe.

A: modulus na sassauci (G′, cikakke) da na asara (G″, a buɗe) gwargwadon mita, ga actin shi kaɗai (ja) da tare da taurarin-nano a zafi uku (rawaya). B: yayin da ake juya zafi (ƙasa) ta tsallaken zafin narkewa, tauri (sama) yana sauyawa gaba da baya. C: modulus na sassauci gwargwadon zafi, ba tare da taurarin-nano ba da kuma tare da 10 ko 38 µM. — Hoto na 3, Wilken et al. (2026), arXiv:2610.38504.

Zare da aka riƙe, maƙwabta da aka ja

Bayani biyu da aka saba bayarwa sun gaza: ƙarfin saman ruwan DNA (surface tension), jan saman digon, ya yi rauni ƙwarai, kuma idan taurarin-nano suna manne zare da juna, da abin ya ƙara tauri sosai ƙarƙashin manyan sauye-sauyen siffa — amma akasin haka ya faru.

A cikin digo, ana matse zaren actin cikin “bututu” mai faɗin kusan nanometre 10 — da ƙyar ya wuce nasu 7 — idan aka kwatanta da kusan nanometre 140 a cikin actin shi kaɗai. Wannan riƙo mai ƙarfi yana mayar da kowane digo da zarensa dunƙule mai tauri. Har yanzu bai isa ba: a kashi 9% na girman, ko dunƙule masu tauri cikakke suna nan cikin iyakar Einstein.

Mabuɗin shi ne murɗawa (shear). Dunƙule mai tauri ba zai iya canza siffa ba, don haka yana juyawa. Zaren da aka riƙe a ciki suna juyawa tare da shi, kuma ɓangarorinsu na waje suna share ragar da ke kewaye, suna jan ta tare; digo mai radius na micrometre 2 yana riƙe da kusan zare 500. Marubutan sun ɗauka cewa yankin da ake ja ya miƙa radius ɗaya na digo bayan saman. Wannan yana ninka radius na aiki na kowane dunƙule biyu kuma yana ninka girmansa na aiki sau 8.

Tare da 10 µM na taurarin-nano, digo suna cike kashi 2.5% na girman, don haka dunƙulen da suka faɗaɗa suna cike 20%. Suna zama a ware; samfuran lissafi na yau da kullum sai su yi hasashen ninkin ƙarin tauri na 1.8, kusa da 2.2 ± 0.3 da aka auna. Tare da 38 µM, 9% ya zama kusan 70%, nesa sama da iyakar — kusan 30% — inda irin waɗannan bawoyi masu shiga juna ke haɗuwa su zama raga mai ci gaba, haɗe da zaren da suke rabawa, da ke riƙe abin da tauri. Ƙarin taurin yana da iyaka: ragar ba ta fi actin da aka matse a cikin kowane digo tauri ba.

A: ninkin ƙarin tauri gwargwadon zafi; layin shi ne hasashen matsewa na marubutan. B: ƙarƙashin murɗawa, digo (ruwan shunayya) yana juyawa kuma yana jan zaren da suka ratsa shi (kore). C: kusa da digo, yawancin zare waɗanda suka tsallaka shi ne; baka yana nuna ninki biyu na radius ɗinsa. D: ƙasa da zafin narkewa, digo tare da da’irar da suke ja suna zama a ware a 10 µM kuma suna haɗuwa su zama raga a 38 µM. — Hoto na 4, Wilken et al. (2026), arXiv:2610.38504.

Digo ɗaya a lokaci guda

Wannan hoton ya dogara ne kan wani zato — yankin da ake ja mai kaurin radius ɗaya daidai — kuma yana ɗaukar kowane digo shi kaɗai. Inda yankuna suka shiga juna, zaren da digo biyu ke rabawa ba za su iya juyawa tare da dukansu ba, matsin da samfurin lissafin ya bari. Ko girman digon da ragar ta ƙayyade yana da tasiri kan ƙarin taurin, ko kuma rabon girma ne kawai, ba a bayyane yake ba. Kuma lanƙwasan jadawalin sun fito ne daga samfura biyu ga kowane yawan taurarin-nano, ɗaya ga actin shi kaɗai.

Marubutan suna kiran wannan alaƙa “ta juna, ba mayar da martani ba” (reciprocal, not feedback): tasiri biyu na hanya ɗaya da ke nuna akasin juna. A ilimin halitta, inda condensates da ragar zare duka suka yaɗu, samuwar digo za ta iya sauya halayen injiniyanci (mechanics) a lokacin da ake buƙata, a cewarsu. A yanzu, a cikin wannan haɗi, ragar ce ke yanke yadda digon za su girma, kuma digon ne ke yanke ƙarfin da ragar za ta mayar da martani da shi.