557:
162:
1155:
47:
1179:
1167:
617:
ascospores. The production of viable ascospores depends on successful recombinational repair during meiosis. When this repair is defective a quality control mechanism prevents germination of damaged ascospores. These findings suggest that mating followed by meiosis is an adaptation for repairing DNA damage in the parental haploid cells in order to allow production of viable progeny ascospores.
144:
416:
616:
is a single-celled haploid organism that reproduces asexually by mitosis and fission. However, exposure to the DNA damaging agent hydrogen peroxide induces pair-wise mating of haploid cells of opposite mating type to form transient diploid cells that then undergo meiosis to form asci, each with four
336:
Asci normally release their spores by bursting at the tip, but they may also digest themselves, passively releasing the ascospores either in a liquid or as a dry powder. Discharging asci usually have a specially differentiated tip, either a pore or an operculum. In some hymenium forming genera, when
499:
ascus is enclosed in a double wall. This consists of a thin, brittle outer shell and a thick elastic inner wall. When the spores are mature, the shell splits open so that the inner wall can take up water. As a consequence this begins to extend with its spores until it protrudes above the rest of
606:
produces ascospores when grown on V-8 medium, acetate ascospore agar, or
Gorodkowa medium. These ascospores are globose and located in asci. Each ascus contains one to four ascospores. The asci do not rupture at maturity. Ascospores are stained with Kinyoun stain and ascospore stain. When stained
303:
of both sets is duplicated, to make a total of four sets. The nucleus that contains the four sets divides twice, separating into four new nuclei – each of which has one complete set of chromosomes. Following this process, each of the four new nuclei duplicates its DNA and undergoes a division by
530:
asci are mostly spherical in shape and have no mechanism for forcible dispersal. The mature ascus wall dissolves allowing the spores to escape, or it is broken open by other influences, such as animals. Asci of this type can be found both in
547:). This is something of a catch-all term for cases which do not fit into the other three ascus types, and they probably belong to several independent groups which evolved separately from unitunicate asci.
337:
one ascus bursts, it can trigger the bursting of many other asci in the ascocarp resulting in a massive discharge visible as a cloud of spores – the phenomenon called "puffing". This is an example of
703:
Zhu, Mo; Riederer, Markus; Hildebrandt, Ulrich (2017). "Very-long-chain aldehydes induce appressorium formation in ascospores of the wheat powdery mildew fungus
Blumeria graminis".
449:, which breaks open when the spores are mature and allows the spores to escape. Unitunicate-operculate asci only occur in those ascocarps which have apothecia, for instance the
261:), and in some cases coenocytic in multiple planes. Mitotic divisions within the developing spores populate each resulting cell in septate ascospores with nuclei. The term
481:
854:
500:
the ascocarp so that the spores can escape into free air without being obstructed by the bulk of the fruiting body. Bitunicate asci occur only in
257:, also filling the asci with smaller cells. Ascospores are nonmotile, usually single celled, but not infrequently may be coenocytic (lacking a
426:
327:, no such structures are found. In rare cases asci of some genera can regularly develop inside older discharged asci one after another, e.g.
1210:
684:
30:
This article is about the spore-bearing cell in fungi. For
Atypical Squamous Cells of Undetermined Significance (ASCUS), see
273:
not used in ascospore formation) that is surrounded by the "bourrelet" (the thickened tissue near the top of the ascus).
642:
1013:
978:
130:
304:
mitosis. As a result, the ascus will contain four pairs of spores. Then the ascospores are released from the ascus.
111:
881:
295:
ones. That is, the single original diploid cell from which the whole process begins contains two complete sets of
83:
187:
68:
90:
433:
The form of the ascus, the capsule which contains the sexual spores, is important for classification of the
464:. Once mature the elastic ring briefly expands and lets the spores shoot out. This type appears both in
1183:
372:
and other phenomena. The formation of asci and their use in genetic analysis are described in detail in
849:
638:
237:
97:
1140:
612:
276:
Typically, a single ascus will contain eight ascospores (or octad). The eight spores are produced by
17:
486:
589:
are formed and released under the humid conditions. After landing onto a suitable surface, unlike
79:
936:
647:
421:
57:
1171:
568:
contained in an ascus, or that was produced inside an ascus. This kind of spore is specific to
180:
64:
674:
1130:
369:
1125:
874:
800:
8:
1135:
556:
509:
235:
cell division. However, asci in some genera or species can occur in numbers of one (e.g.
804:
607:
with Gram stain, ascospores are gram-negative while vegetative cells are gram-positive.
907:
823:
788:
446:
384:
360:, have been used in laboratories for studying the process of meiosis, because the four
764:
739:
1205:
1074:
828:
769:
720:
680:
585:
540:
356:
338:
167:
35:
755:
1094:
903:
818:
808:
759:
751:
712:
404:
400:
104:
867:
813:
716:
659:
505:
149:
31:
1159:
1033:
951:
740:"Sexual reproduction as a response to H2O2 damage in Schizosaccharomyces pombe"
536:
380:
361:
241:), two, four, or multiples of four. In a few cases, the ascospores can bud off
213:
154:
789:"A quality control mechanism linking meiotic success to release of ascospores"
1199:
1028:
921:
634:
602:
501:
368:
coding for spore color and nutritional requirements, the biologist can study
512:(which were formerly united in the old class Loculoascomycetes). Examples:
997:
931:
890:
832:
724:
461:
773:
415:
1038:
926:
532:
469:
161:
1059:
1018:
1005:
859:
577:
573:
517:
465:
434:
329:
313:, in a fruiting body which is visible to the naked eye, here called an
296:
217:
251:) with hundreds of conidia, or the ascospores may fragment, e.g. some
1069:
988:
983:
348:
270:
253:
193:
46:
1109:
1064:
1023:
1001:
941:
388:
315:
309:
247:
946:
676:
Ascomycete
Systematics: Problems and Perspectives in the Nineties
590:
396:
392:
292:
285:
281:
277:
242:
232:
228:
894:
343:
288:
258:
1104:
1054:
969:
569:
565:
450:
324:
220:
209:
399:
and ultimately internal ascospore formation. Members of the
364:
produced by meiosis line up in regular order. By modifying
143:
1099:
365:
307:
In many cases the asci are formed in a regular layer, the
341:. A faint hissing sound can also be heard for species of
300:
698:
696:
480:
391:. The compatible nuclei of the dikaryon merge forming a
702:
855:
693:
633:
737:
71:. Unsourced material may be challenged and removed.
387:at their base. The croziers help maintain a brief
284:division. Two meiotic divisions turn the original
1197:
460:ascus has an elastic ring that functions like a
597:showed a more variable developmental patterns.
786:
672:
666:
875:
780:
882:
868:
269:, refers to the epiplasm (the portion of
822:
812:
763:
323:. In other cases, such as single-celled
131:Learn how and when to remove this message
889:
555:
479:
414:
165:There are 8 ascospores in each ascus of
160:
142:
34:. For the Greek mythological giant, see
453:. 'Unitunicate' means 'single-walled'.
437:. There are four basic types of ascus.
14:
1198:
560:Sordaria fimicola ascus plus ascospore
299:. In preparation for meiosis, all the
27:Spore-bearing cell in ascomycete fungi
863:
425:(they are unitunicate-inoperculate).
1166:
524:(Brown Leaf Mold of Horse Chestnut).
223:. Each ascus usually contains eight
69:adding citations to reliable sources
40:
1178:
738:Bernstein C, Johns V (April 1989).
201:
24:
504:and are found only in the classes
490:containing a tetrad of four spores
25:
1222:
843:
410:
1177:
1165:
1154:
1153:
472:; an example is the illustrated
231:followed, in most species, by a
45:
850:IMA Mycological Glossary: Ascus
756:10.1128/jb.171.4.1893-1897.1989
383:develop after the formation of
56:needs additional citations for
731:
627:
13:
1:
1211:Fungal morphology and anatomy
620:
551:
245:that may fill the asci (e.g.
814:10.1371/journal.pone.0082758
717:10.1016/j.funbio.2017.05.003
395:nucleus that then undergoes
200: 'skin bag, wineskin';
7:
456:Instead of an operculum, a
10:
1227:
238:Monosporascus cannonballus
186:
29:
1149:
1141:List of mycology journals
1118:
1087:
1047:
967:
960:
914:
901:
679:. Springer. p. 116.
613:Schizosaccharomyces pombe
487:Saccharomyces cerevisiae
458:unitunicate-inoperculate
227:(or octad), produced by
787:Guo H, King MC (2013).
673:Hawksworth DL. (2013).
648:A Greek-English Lexicon
474:Hypomyces chrysospermus
445:ascus has a "lid", the
422:Hypomyces chrysospermus
354:Asci, notably those of
561:
491:
443:unitunicate-operculate
430:
407:do not form croziers.
172:
158:
1131:List of fungal orders
559:
483:
418:
164:
146:
1126:Glossary of mycology
539:, for instance with
65:improve this article
1136:List of mycologists
805:2013PLoSO...882758G
514:Venturia inaequalis
510:Chaetothyriomycetes
908:Outline of lichens
610:The fission yeast
583:The ascospores of
564:An ascospore is a
562:
522:Guignardia aesculi
492:
431:
291:nucleus into four
173:
159:
1193:
1192:
1083:
1082:
979:teleomorph/sexual
686:978-1-4757-9290-4
595:Blumeria graminis
586:Blumeria graminis
541:Dutch elm disease
374:Neurospora crassa
357:Neurospora crassa
339:positive feedback
168:Sordaria fimicola
141:
140:
133:
115:
36:Ascus (mythology)
16:(Redirected from
1218:
1181:
1180:
1169:
1168:
1157:
1156:
1014:anamorph/asexual
965:
964:
904:Outline of fungi
884:
877:
870:
861:
860:
837:
836:
826:
816:
784:
778:
777:
767:
735:
729:
728:
700:
691:
690:
670:
664:
663:
657:
655:
631:
593:, ascospores of
405:Saccharomycotina
401:Taphrinomycotina
208:) is the sexual
203:
197:
190:
136:
129:
125:
122:
116:
114:
73:
49:
41:
21:
1226:
1225:
1221:
1220:
1219:
1217:
1216:
1215:
1196:
1195:
1194:
1189:
1145:
1114:
1095:Dimorphic fungi
1088:Growth patterns
1079:
1043:
956:
937:Medicinal fungi
910:
897:
888:
846:
841:
840:
785:
781:
736:
732:
701:
694:
687:
671:
667:
660:Perseus Project
653:
651:
632:
628:
623:
554:
506:Dothideomycetes
413:
150:Morchella elata
137:
126:
120:
117:
74:
72:
62:
50:
39:
32:Bethesda system
28:
23:
22:
15:
12:
11:
5:
1224:
1214:
1213:
1208:
1191:
1190:
1188:
1187:
1175:
1163:
1150:
1147:
1146:
1144:
1143:
1138:
1133:
1128:
1122:
1120:
1116:
1115:
1113:
1112:
1107:
1102:
1097:
1091:
1089:
1085:
1084:
1081:
1080:
1078:
1077:
1072:
1067:
1062:
1057:
1051:
1049:
1045:
1044:
1042:
1041:
1036:
1031:
1026:
1021:
1009:
1008:
995:
986:
974:
972:
962:
958:
957:
955:
954:
952:Mycotoxicology
949:
944:
939:
934:
929:
924:
918:
916:
912:
911:
902:
899:
898:
887:
886:
879:
872:
864:
858:
857:
852:
845:
844:External links
842:
839:
838:
799:(12): e82758.
779:
730:
711:(8): 716–728.
705:Fungal Biology
692:
685:
665:
625:
624:
622:
619:
572:classified as
553:
550:
549:
548:
525:
478:
477:
462:pressure valve
454:
412:
411:Classification
409:
381:Pezizomycotina
280:followed by a
263:ocular chamber
155:Phase contrast
139:
138:
53:
51:
44:
26:
9:
6:
4:
3:
2:
1223:
1212:
1209:
1207:
1204:
1203:
1201:
1186:
1185:
1176:
1174:
1173:
1164:
1162:
1161:
1152:
1151:
1148:
1142:
1139:
1137:
1134:
1132:
1129:
1127:
1124:
1123:
1121:
1117:
1111:
1108:
1106:
1103:
1101:
1098:
1096:
1093:
1092:
1090:
1086:
1076:
1073:
1071:
1068:
1066:
1063:
1061:
1058:
1056:
1053:
1052:
1050:
1046:
1040:
1037:
1035:
1032:
1030:
1029:Chlamydospore
1027:
1025:
1022:
1020:
1017:
1015:
1011:
1010:
1007:
1003:
999:
996:
994:
990:
987:
985:
982:
980:
976:
975:
973:
971:
968:Reproduction/
966:
963:
959:
953:
950:
948:
945:
943:
940:
938:
935:
933:
930:
928:
925:
923:
922:Ethnomycology
920:
919:
917:
913:
909:
905:
900:
896:
892:
885:
880:
878:
873:
871:
866:
865:
862:
856:
853:
851:
848:
847:
834:
830:
825:
820:
815:
810:
806:
802:
798:
794:
790:
783:
775:
771:
766:
761:
757:
753:
750:(4): 1893–7.
749:
745:
741:
734:
726:
722:
718:
714:
710:
706:
699:
697:
688:
682:
678:
677:
669:
661:
650:
649:
644:
640:
636:
635:Henry Liddell
630:
626:
618:
615:
614:
608:
605:
604:
603:Saccharomyces
598:
596:
592:
588:
587:
581:
579:
575:
571:
567:
558:
546:
542:
538:
537:cleistothecia
534:
529:
528:Prototunicate
526:
523:
519:
515:
511:
507:
503:
498:
494:
493:
489:
488:
482:
475:
471:
467:
463:
459:
455:
452:
448:
444:
440:
439:
438:
436:
428:
424:
423:
417:
408:
406:
402:
398:
394:
390:
386:
382:
379:Asci of most
377:
375:
371:
370:crossing over
367:
363:
359:
358:
352:
350:
346:
345:
340:
334:
332:
331:
326:
322:
318:
317:
312:
311:
305:
302:
298:
294:
290:
287:
283:
279:
274:
272:
268:
264:
260:
256:
255:
250:
249:
244:
240:
239:
234:
230:
226:
222:
219:
215:
211:
207:
199:
196:
189:
185:
182:
181:Ancient Greek
178:
170:
169:
163:
156:
152:
151:
145:
135:
132:
124:
113:
110:
106:
103:
99:
96:
92:
89:
85:
82: –
81:
77:
76:Find sources:
70:
66:
60:
59:
54:This article
52:
48:
43:
42:
37:
33:
19:
1182:
1170:
1158:
1012:
998:Basidiospore
992:
977:
932:Marine fungi
891:Microbiology
796:
792:
782:
747:
744:J. Bacteriol
743:
733:
708:
704:
675:
668:
658:– via
652:. Retrieved
646:
639:Robert Scott
629:
611:
609:
601:
599:
594:
584:
582:
563:
544:
527:
521:
513:
502:pseudothecia
496:
485:
473:
457:
442:
432:
420:
378:
373:
355:
353:
342:
335:
328:
320:
314:
308:
306:
275:
266:
262:
252:
246:
236:
224:
216:produced in
205:
194:
191:
184:
176:
174:
166:
148:
127:
118:
108:
101:
94:
87:
75:
63:Please help
58:verification
55:
1184:WikiProject
1039:Pycniospore
927:Lichenology
654:27 February
574:ascomycetes
297:chromosomes
1200:Categories
1060:Haustorium
1019:Sporangium
1006:Teliospore
621:References
600:The fungi
578:Ascomycota
552:Ascospores
545:Ophiostoma
533:perithecia
518:apple scab
497:bitunicate
470:perithecia
435:Ascomycota
347:and other
330:Dipodascus
225:ascospores
218:ascomycete
179:(from
91:newspapers
1075:Sporocarp
1070:Cell wall
989:Ascospore
984:Zygospore
961:Structure
484:Ascus of
466:apothecia
447:Operculum
349:cup fungi
271:cytoplasm
254:Cordyceps
212:-bearing
121:June 2015
18:Ascospore
1206:Mycology
1160:Category
1110:Mushroom
1065:Mycelium
1024:Conidium
1002:Basidium
942:Mycology
833:24312672
793:PLOS ONE
725:28705398
419:Asci of
389:dikaryon
385:croziers
316:ascocarp
310:hymenium
248:Tympanis
147:Asci of
1172:Commons
947:Mycosis
824:3846778
801:Bibcode
774:2703462
643:"ἀσκός"
591:conidia
535:and in
520:) and
468:and in
397:meiosis
393:diploid
293:haploid
286:diploid
282:mitotic
278:meiosis
243:conidia
233:mitotic
229:meiosis
105:scholar
80:"Ascus"
1034:Oidium
915:Branch
895:Fungus
831:
821:
772:
765:209837
762:
723:
683:
451:morels
429:image.
344:Peziza
325:yeasts
321:ascoma
289:zygote
267:oculus
259:septum
107:
100:
93:
86:
78:
1105:Yeast
1055:Hypha
1048:Other
993:Ascus
970:spore
570:fungi
566:spore
366:genes
362:cells
265:, or
221:fungi
210:spore
195:askós
188:ἀσκός
183:
177:ascus
157:image
112:JSTOR
98:books
1119:List
1100:Mold
829:PMID
770:PMID
721:PMID
681:ISBN
656:2018
508:and
403:and
214:cell
206:asci
84:news
819:PMC
809:doi
760:PMC
752:doi
748:171
713:doi
709:121
580:).
427:DIC
319:or
301:DNA
202:pl.
175:An
67:by
1202::
906:·
893::
827:.
817:.
807:.
795:.
791:.
768:.
758:.
746:.
742:.
719:.
707:.
695:^
645:.
641:.
637:;
495:A
441:A
376:.
351:.
333:.
204::
153:,
1016::
1004:/
1000:/
991:/
981::
883:e
876:t
869:v
835:.
811::
803::
797:8
776:.
754::
727:.
715::
689:.
662:.
576:(
543:(
516:(
476:.
198:)
192:(
171:.
134:)
128:(
123:)
119:(
109:·
102:·
95:·
88:·
61:.
38:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
