Growth, Differentiation and Sexuality

More documents

Recommendations

Info

The fact that fruiting-body formation requires high amounts of energy in the form of carbohydrates initially stored in vegetative hyphae, and subsequently released mostly in the extracellular space, would imply the existence of effective transport systems for nutrient uptake into the cells of the developing fruiting body. One such transporter for hexoses that is localized in ascogenous hyphae was described in A. nidulans (Wei et al. 2004). The gene for this transporter, hxtA, is not essential for sexual development, but as there are at least 17 putative hexose transporter genes in the A. nidulans genome, this might be due to the existence of functionally redundant proteins (Wei et al. 2004). 3. Pigments Other common components of fungal cell walls are pigments, e.g., brown or black melanins. Melanins stabilize the cell wall and offer protection against UV light-induced DNA damage, but also have additional functions. For example, they are necessary for appressorial penetration of plant tissue in several fungal plant pathogens, and for pathogenicity of several human pathogens (Howard and Valent 1996; Perpetua et al. 1996; Jacobson 2000). Two biochemical pathways have been recognized for fungal melanin production, the DHN (dihydroxynaphtalene)- and the DOPA (dihydroxyphenylalanine)-melanin biosynthesis pathways (Langfelder et al. 2003). Both pathways contain laccases for the first (DOPA) or last (DHN) biosynthetic step, respectively. The DHN pathway involves a polyketide synthase in its initial step, but laccases and polyketide synthases also participate in a variety of biosynthetic pathways not necessarily involved in pigment formation. Laccase and polyketide synthase genes have been identified in several fungi, and have been implied in fruiting-body pigmentation of ascomycetes, but so far evidence for a genetic control of melanin biosynthesis in black or darkly pigmented fruiting bodies is missing. It was shown for A. nidulans that laccase activity is located in young cleistothecia and Hülle cells, and that a sterile mutant had reduced laccase activity, but the corresponding laccase gene(s) have not yet been identified (Kurtz and Champe 1981; Hermann et al. 1983). In the plant pathogen Nectria haematococca, a polyketide synthase, PKSN, was showntobeessentialforthesynthesisofthered perithecial pigment by complementation of a mu- Fruiting Bodies in Ascomycetes 347 tant with white perithecia (Graziani et al. 2004). The mutant, however, is fertile. Therefore, the lack of perithecial pigmentation does not preclude ascospore maturation (Babai-Ahary et al. 1982), although it might be interesting to determine performance of the mutant strain under natural growth conditions. 4. Cell Wall Proteins In addition to carbohydrates and pigment molecules, proteins comprise a sizeable part of the fungal cell wall. Two classes of proteins, hydrophobins and lectins, have been characterized extensively in higher basidiomycetes where they are implied in mushroom formation (see also Chap. 19, this volume). Hydrophobins can selfassemble at water/air interfaces, and form highly insoluble amphipathic films. These films can attach to the hydrophilic cellular surfaces, thereby orienting the hydrophobic side to the outside, which allows the fungus to break a water/air interface and grow into the air (Wösten et al. 1999). Lectins are carbohydrate-binding, mostly extracellular proteins that occur in virtually all classes of organisms. They have been implicated in the interaction of fungi with other organisms as well as fruiting-body formation in basidiomycetes (Walser et al. 2003). Genes encoding hydrophobins and lectins have been found in ascomycetes, too, but whether any of these play a role in sexual development is not yet clear. Hydrophobins from N. crassa, A. nidulans and M. grisea have been shown to be involved in the formation of the water-repellent coat of conidiospores, but not in fruiting-body development (Stringer et al. 1991; Bell-Pedersen et al. 1992; Stringer and Timberlake 1995; Talbot et al. 1996). As fungi can contain several members of the hydrophobin family in their genomes (Segers et al. 1999; Fuchs et al. 2004), addressing the question whether any of these are involved in fruiting-body morphogenesis might be a complex task involving the generation of mutants in more than one hydrophobin gene. Similarly to hydrophobins, lectins are thought to be involved in fruiting-body formation, but a requirement for lectins has yet to beshowninanyfungus.Theonlydescribedmutant in a lectin-encoding gene of an ascomycete is the aol mutant of Arthrobotrys oligospora (Balogh et al. 2003), but as no perfect stage of A. oligospora is known, the question of an involvement of AOL in sexual development cannot be addressed.
348 S. Pöggeler et al. 5. Are Multiple Genes with Overlapping Functions Involved in Cell Wall Metabolism? The information about the molecular and genetic basis of cell wall metabolism during fruiting-body formation in ascomycetes is rather limited. A recurring theme are mutants in “candidate genes” that surprisingly do not have any discernible phenotype (see Sect. IV.B.2–4). Especially with the availability of whole genome sequences, it has become increasingly clear that one of the reasons for these findings might be the existence of large gene families most likely with partly overlapping functions. This does seem to be the case for most of the genes involved in the biosynthesis of cell wall components. A possible explanation for this might be the fact that the cell wall is a highly important structure for fungi – it is form-giving as well as protecting – but makes assessments of single components somewhat tedious. However, analysis of whole genome data, especially cross-species comparisons as well as large-scale expression studies, could help to identify candidates for future gene inactivation projects. V. Conclusions Fruiting-body formation in filamentous ascomycetes is a highly complex differentiation process that in some cases produces up to 15 different cell types. This complexity is further enhanced by morphogenic signals, such as light, temperature, and nutrients as well as species-specific cell communication factors such as pheromones and other signaling molecules. The many parameters determining this process may explain why several genes encoding G proteins, receptors, pheromones, and transcription factors have been identified as being involved in this developmental process. Mainly two different signal transduction pathways, MAPK cascades, and a cAMP-PKA cascade, function coordinately to regulate sexual cell differentiation processes by activating or repressing numerous transcription factors of different classes. Most probably, these regulate the transcription of genes encoding enzymes involved in cell wall biogenesis and metabolism, and genes for cytoskeleton structure and organization. Classical genetic studies have shown that ascocarp development involves a series of developmentally regulated genes. Therefore, it seems not surprising that currently no “main stream” signal transduction pathway is obvious that predominantly directs fruiting-body development in ascomycetes. In summary, it has become evident that multicellular ascocarp development requires precise integration of a number of fundamental biological processes. The sexual pathway in ascomycetes provides a valuable experimental system for studying the mechanism and regulation of developmental processes that are usually more complex in animal and plant development. The analysis of fungal genomes is a starting point for further understanding developmental processes in mycelial fungi and other multicellular eukaryotes. Post-genomic analysis, including transcriptome and proteome assessments, will hopefully decipher components directing multicellular differentiation processes in ascomycetes, and finally as a long-term objective will help to understand eukaryotic differentiation processes at the molecular level. Acknowledgements.WethankDr.S.MasloffandDr.S.Risch for microscopic images. The work of the authors is funded by the ‘Deutsche Forschungsgemeinschaft’ (DFG). References Adachi K, Hamer JE (1998) Divergent cAMP signaling pathways regulate growth and pathogenesis in the rice blast fungus Magnaporthe grisea. Plant Cell 10:1361–1374 Adams TH, Wieser JK, Yu J-H (1998) Asexual sporulation in Aspergillus nidulans. Microbiol Mol Biol Rev 62:35–54 Alex LA, Borkovich KA, Simon MI (1996) Hyphal development in Neurospora crassa: involvement of a twocomponent histidine kinase. Proc Natl Acad Sci USA 93:3416–3421 Alexopoulos CJ, Mims CW, Blackwell M (1996) Introductory mycology. Wiley, New York Almeida T, Duarte M, Melo AM, Videira A (1999) The 24kDa iron-sulphur subunit of complex I is required for enzyme activity. Eur J Biochem 265:86–93 Aramayo R, Peleg Y, Addison R, Metzenberg R (1996) Asm-1 + ,aNeurospora crassa gene related to transcriptional regulators of fungal development. Genetics 144:991–1003 Arnaise S, Zickler D, Poisier C, Debuchy R (2001) pah1: a homeobox gene involved in hyphal morphology and microconidiogenesis in the filamentous ascomycete Podospora anserina. Mol Microbiol 39:54–64 Baasiri RA, Lu X, Rowley PS, Turner GE, Borkovich KA (1997) Overlapping functions for two G protein α subunits in Neurospora crassa. Genetics 147:137–145 Babai-Ahary A, Daboussi-Bareyre MJ, Parisot D (1982) Isolation and genetic analysis of self-sterility and perithecial pigmentation mutants in a homothallic isolate of Nectria haematococca. Can J Bot 60:79–84 Bailey LA, Ebbole DJ (1998) The fluffy gene of Neurospora crassa encodes a Gal4p-type C6 zinc cluster protein required for conidial development. Genetics 148:1813– 1820
Page 2 and 3:
The Mycota Edited by K. Esser
Page 4 and 5:
The Mycota A Comprehensive Treatise
Page 6 and 7:
Karl Esser (born 1924) is retired P
Page 8 and 9:
VIII Series Preface Class: Saccharo
Page 10 and 11:
Addendum to the Series Preface In e
Page 12 and 13:
XIV Volume Preface to the First Edi
Page 14 and 15:
XVI Volume Preface to the Second Ed
Page 16 and 17:
XVIII Contents Reproductive Process
Page 18 and 19:
XX List of Contributors André Flei
Page 20 and 21:
Vegetative Processes and Growth
Page 22 and 23:
4 K.J. Boyce and A. Andrianopoulos
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
22 L.J. García-Rodríguez et al. I
Page 42 and 43:
24 L.J. García-Rodríguez et al. F
Page 44 and 45:
26 L.J. García-Rodríguez et al. 2
Page 46 and 47:
28 L.J. García-Rodríguez et al. M
Page 48 and 49:
30 L.J. García-Rodríguez et al. a
Page 50 and 51:
32 L.J. García-Rodríguez et al. t
Page 52 and 53:
34 L.J. García-Rodríguez et al. H
Page 54 and 55:
36 L.J. García-Rodríguez et al. T
Page 56 and 57:
38 S.D. Harris dle organization tha
Page 58 and 59:
40 S.D. Harris 2001; Borkovich et a
Page 60 and 61:
42 S.D. Harris terized in A. nidula
Page 62 and 63:
44 S.D. Harris astral microtubules
Page 64 and 65:
46 S.D. Harris entry, and the CDK N
Page 66 and 67:
48 S.D. Harris and Hamer 1997), the
Page 68 and 69:
50 S.D. Harris Murray AW (2004) Rec
Page 70 and 71:
4 Apical Wall Biogenesis J.H. Siets
Page 72 and 73:
fungi can be regarded as “tube-dw
Page 74 and 75:
In agreement with an essential role
Page 76 and 77:
Kopecka and Gabriel 1992). They als
Page 78 and 79:
nearly all the label was present in
Page 80 and 81:
ingredients such as wall components
Page 82 and 83:
in membrane enlargement and exocyto
Page 84 and 85:
sis occurs, coinciding with a gradi
Page 86 and 87:
pling of two (1-3)-alpha-glucan seg
Page 88 and 89:
Sietsma JH, Wessels JGH (1977) Chem
Page 90 and 91:
5 The Fungal Cell Wall J.P. Latgé
Page 92 and 93:
polymers (chitosan) and glucuronic
Page 94 and 95:
Whereas the structural branched β1
Page 96 and 97:
their structural role in the cell w
Page 98 and 99:
eight chitin synthases of A. fumiga
Page 100 and 101:
Characterization of the chs4 mutant
Page 102 and 103:
Fig. 5.8. Experimental data and hyp
Page 104 and 105:
Fig. 5.9. Elongation of the mannan
Page 106 and 107:
end of linear β1,3 glucans, and tr
Page 108 and 109:
Fig. 5.12. Signal transduction in f
Page 110 and 111:
shock,lowosmolarityaswellasotherfac
Page 112 and 113:
ditions. Accordingly, enzymes and r
Page 114 and 115:
Calonge TM, Arellano M, Coll PM, Pe
Page 116 and 117:
Hiura N, Nakajima T, Matsuda K (198
Page 118 and 119:
Martin-Yken H, Dagkessamanskaia A,
Page 120 and 121:
Saporito-Irwin SM, Birse CE, Sypher
Page 122 and 123:
6 Septation and Cytokinesis in Fung
Page 124 and 125:
Septation in Fungi 107 Table. 6.1.
Page 126 and 127:
Fig. 6.1. Selection of a cell divis
Page 128 and 129:
Calderone, Chap. 5, this volume, an
Page 130 and 131:
permissive temperature, multiple se
Page 132 and 133:
eports suggested such a function fo
Page 134 and 135:
understood mechanism of mitotic exi
Page 136 and 137:
Implication in cytokinesis in Sacch
Page 138 and 139:
Trinci APJ, Morris NR (1979) Morpho
Page 140 and 141:
124 N.L. Glass and A. Fleissner ter
Page 142 and 143:
126 N.L. Glass and A. Fleissner 188
Page 144 and 145:
128 N.L. Glass and A. Fleissner Fig
Page 146 and 147:
130 N.L. Glass and A. Fleissner sub
Page 148 and 149:
132 N.L. Glass and A. Fleissner dur
Page 150 and 151:
134 N.L. Glass and A. Fleissner G1
Page 152 and 153:
136 N.L. Glass and A. Fleissner Bri
Page 154 and 155:
138 N.L. Glass and A. Fleissner Mat
Page 156 and 157:
8 Heterogenic Incompatibility in Fu
Page 158 and 159:
Fungal Heterogenic Incompatibility
Page 160 and 161:
B. Genetic Control The genetic back
Page 162 and 163:
active phenotype het-s. The neutral
Page 164 and 165:
Table. 8.1. (continued) Fungal Hete
Page 166 and 167:
is a complex genetic trait controll
Page 168 and 169:
indicate how speciation may be init
Page 170 and 171:
ility controlled by multiple allele
Page 172 and 173:
dependonthematingtypegenes,wasobser
Page 174 and 175:
6. Relation with Histo-Incompatibil
Page 176 and 177:
Semi-Incompatibilität. Z Indukt Ab
Page 178 and 179:
Micali CO, Smith ML (2003) On the i
Page 180 and 181:
Vilgalys RJ, Miller OK (1987) Matin
Page 182 and 183:
168 B.C.K. Lu (Esser et al. 1980; K
Page 184 and 185:
170 B.C.K. Lu enterthePCDpathway,wi
Page 186 and 187:
172 B.C.K. Lu et al. 2004). It is l
Page 188 and 189:
174 B.C.K. Lu (MMP), through ruptur
Page 190 and 191:
176 B.C.K. Lu Fig. 9.1. Effects of
Page 192 and 193:
178 B.C.K. Lu drial fission during
Page 194 and 195:
180 B.C.K. Lu Although the cytologi
Page 196 and 197:
182 B.C.K. Lu be arrested at diffus
Page 198 and 199:
184 B.C.K. Lu Harris MH, Thompson C
Page 200 and 201:
186 B.C.K. Lu oxygen species, in Kl
Page 202 and 203:
10 Senescence and Longevity H.D. Os
Page 204 and 205:
the amplification of plDNA is not a
Page 206 and 207:
GRISEA is an orthologue of the yeas
Page 208 and 209:
Fig. 10.3. Copper delivery to the c
Page 210 and 211:
have been identified, for example,
Page 212 and 213:
Kück U, Stahl U, Esser K (1981) Pl
Page 214 and 215:
Signals in Growth and Development
Page 216 and 217:
204 U. Ugalde II. Germination The p
Page 218 and 219:
206 U. Ugalde Fig. 11.2.A-C Drawing
Page 220 and 221:
208 U. Ugalde duction (Schimmel et
Page 222 and 223:
210 U. Ugalde position, possibly in
Page 224 and 225:
212 U. Ugalde Champe SP, Rao P, Cha
Page 226 and 227:
12 Pheromone Action in the Fungal G
Page 228 and 229:
sibly due to displacement of the hy
Page 230 and 231:
all these compounds, the B-derivate
Page 232 and 233:
shows the same activity in M. muced
Page 234 and 235:
C. Oomycota In the non-mycotan phyl
Page 236 and 237:
following sequence of events has be
Page 238 and 239:
the standard Mendelian segregation
Page 240 and 241:
Elliott CG, Knights BA (1981) Uptak
Page 242 and 243:
constitutively transcribed but its
Page 244 and 245:
234 L.M. Corrochano and P. Galland
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Reproductive Processes
Page 272 and 273:
264 R. Fischer and U. Kües 2. Chla
Page 274 and 275:
266 R. Fischer and U. Kües resourc
Page 276 and 277:
268 R. Fischer and U. Kües ular le
Page 278 and 279:
270 R. Fischer and U. Kües pathway
Page 280 and 281:
272 R. Fischer and U. Kües and con
Page 282 and 283:
274 R. Fischer and U. Kües Timberl
Page 284 and 285:
276 R. Fischer and U. Kües PsiB le
Page 286 and 287:
278 R. Fischer and U. Kües Table.
Page 288 and 289:
280 R. Fischer and U. Kües tein ki
Page 290 and 291:
282 R. Fischer and U. Kües nitroge
Page 292 and 293:
284 R. Fischer and U. Kües tion, t
Page 294 and 295:
286 R. Fischer and U. Kües Busch S
Page 296 and 297:
288 R. Fischer and U. Kües Jeffs L
Page 298 and 299:
290 R. Fischer and U. Kües Pöggel
Page 300 and 301:
292 R. Fischer and U. Kües Yamashi
Page 302 and 303:
294 R. Debuchy and B.G. Turgeon tha
Page 304 and 305: 296 R. Debuchy and B.G. Turgeon loc
Page 306 and 307: 298 R. Debuchy and B.G. Turgeon Tab
Page 308 and 309: 300 R. Debuchy and B.G. Turgeon Fig
Page 310 and 311: 302 R. Debuchy and B.G. Turgeon mai
Page 312 and 313: 304 R. Debuchy and B.G. Turgeon mol
Page 314 and 315: 306 R. Debuchy and B.G. Turgeon gen
Page 316 and 317: 308 R. Debuchy and B.G. Turgeon int
Page 318 and 319: 310 R. Debuchy and B.G. Turgeon Fig
Page 320 and 321: 312 R. Debuchy and B.G. Turgeon pro
Page 322 and 323: 314 R. Debuchy and B.G. Turgeon B.
Page 324 and 325: 316 R. Debuchy and B.G. Turgeon 2.
Page 326 and 327: 318 R. Debuchy and B.G. Turgeon in
Page 328 and 329: 320 R. Debuchy and B.G. Turgeon be
Page 330 and 331: 322 R. Debuchy and B.G. Turgeon Lee
Page 332 and 333: 16 Fruiting-Body Development in Asc
Page 334 and 335: phae originating from the base of a
Page 336 and 337: Table. 16.1. (continued) Fruiting B
Page 338 and 339: (Raju 1992). When male-sterile muta
Page 340 and 341: 1. nsd (never in sexual development
Page 342 and 343: egular intervals; both effects requ
Page 344 and 345: the balance between sexual and asex
Page 346 and 347: ductionofeitherpheromoneisdirectlyc
Page 348 and 349: (Catlett et al. 2003). Eleven genes
Page 350 and 351: negative mutation of KREV-1 resulte
Page 352 and 353: through MAP kinase modules to cell-
Page 356 and 357: Balestrini R, Mainieri D, Soragni E
Page 358 and 359: point mutation of the beta subunit
Page 360 and 361: Mitchell TK, Dean RA (1995) The cAM
Page 362 and 363: YamashiroCT,EbboleDJ,LeeBU,BrownRE,
Page 364 and 365: 358 L.A. Casselton and M.P. Challen
Page 382 and 383: 376 M. Feldbrügge et al. different
Page 384 and 385: 378 M. Feldbrügge et al. Fig. 18.3
Page 386 and 387: 380 M. Feldbrügge et al. et al. 20
Page 388 and 389: 382 M. Feldbrügge et al. for unbia
Page 390 and 391: 384 M. Feldbrügge et al. In U. may
Page 392 and 393: 386 M. Feldbrügge et al. Neurospor
Page 394 and 395: 388 M. Feldbrügge et al. Bernards
Page 396 and 397: 390 M. Feldbrügge et al. O’Donne
Page 398 and 399: 19 The Emergence of Fruiting Bodies
Page 400 and 401: 2003; Kües et al. 2004) are the fi
Page 402 and 403: (Manachère 1988), C. cinereus (Tsu
Page 404 and 405:
emergence of fruiting bodies. In th
Page 406 and 407:
Rather, development is arrested in
Page 408 and 409:
10 nm thick is highly insoluble and
Page 410 and 411:
it has been suggested that hydropho
Page 412 and 413:
expression in the stipe suggests th
Page 414 and 415:
Cooper DNW, Boulianne RP, Charlton
Page 416 and 417:
Lu BC (1974) Meiosis in Coprinus. R
Page 418 and 419:
Takagi Y, Katayose Y, Shishido K (1
Page 420 and 421:
20 Meiosis in Mycelial Fungi D. Zic
Page 422 and 423:
Fig. 20.1. A-E Diagrammatic represe
Page 424 and 425:
etween dispersed DNA repeats. In N.
Page 426 and 427:
Fig. 20.2. Meiotic recombination. S
Page 428 and 429:
mechanism whereby homologues locate
Page 430 and 431:
An important component of the bouqu
Page 432 and 433:
observed when the mammal LE compone
Page 434 and 435:
A. Chromosome and Sister-Chromatid
Page 436 and 437:
ascus plus ascospore morphogenesis
Page 438 and 439:
syndrome)discoveredasageneinvolvedi
Page 440 and 441:
Kitajima TS, Kawashima SA, Watanabe
Page 442 and 443:
Rossignol J-L, Faugeron G (1995) MI
Page 444 and 445:
Biosystematic Index Absidia glauca
Page 446 and 447:
violaceum 153 Microsporum 149 Mimos
Page 448 and 449:
Subject Index ABC transporter 382 a
Page 450 and 451:
fluffy 270, 276 formin 8, 10, 13, 1
Page 452 and 453:
MAT protein interaction 308, 315 ma
Page 454:
sporangiophore 234, 242, 246-252, 2
show all

Growth, Differentiation and Sexuality

Create successful ePaper yourself

Delete template?

Save as template?