The fungus-farming ant genus Cyphomyrmex (subtribe Attina, clade Neoattina) comprises 23 described species that are widely distributed throughout the Neotropics. Species within Cyphomyrmex have taxonomic issues such as Cyphomyrmex rimosus (Spinola, 1851) which is likely a species complex. Cytogenetics is a useful tool for evolutionary studies and understanding species with dubious taxonomy. In this study, we characterized the karyotype of C. rimosus from Viçosa, Minas Gerais State, southeastern Brazil using classical and molecular cytogenetic techniques to enrich the chromosomal information about Cyphomyrmex. The karyotype of C. rimosus from the rainforest of southeastern Brazil (2n = 22, 18m + 4sm) notably contrasts with that previously described for this species in Panama (2n = 32). This intraspecific chromosomal variation suggests the existence of a species complex within this taxon according to the previous hypothesis derived from morphological analysis. We detected GC-rich heterochromatic regions in C. rimosus and, using repetitive DNA probes, showed that this heterochromatin shares repetitive sequences with other Neoattina species already studied, enhancing the importance of this specific genome region in the understanding of Attina evolution. Mapping of microsatellite (GA)15 on C. rimosus was restricted to the euchromatic regions of all chromosomes. The single intrachromosomal rDNA sites observed in C. rimosus follow the general genomic organization trend of ribosomal genes in Formicidae. Our study extends the data of chromosome mapping on Cyphomyrmex and reinforces the importance of cytogenetic studies in different localities to better understand taxonomic issues in widely distributed taxa such as C. rimosus.

1.
Aguiar
HJAC
,
Barros
LAC
,
Silveira
LI
,
Petitclerc
F
,
Etienne
S
,
Orivel
J
.
Cytogenetic data for sixteen ant species from North-Eastern Amazonia with phylogenetic insights into three subfamilies
.
Comp Cytogenet
.
2020
;
14
(
1
):
43
60
.
2.
Albuquerque
EM
.
Revisão taxonômica e análise filogenética do grupo Rimosus de Cyphomyrmex (Hymenoptera, Formicidae, Attini).
São Paulo:
Universidade São Paulo
;
2014
.
3.
Barros
LAC
,
Mariano
CSF
,
Pompolo
SG
.
Cytogenetic studies of five taxa of the tribe Attini (Formicidae: Myrmicinae)
.
Caryologia
.
2013
;
66
(
1
):
59
64
.
4.
Barros
LAC
,
Chaul
JCM
,
Orivel
J
,
Aguiar
HJAC
.
Cytogenetics of Strumigenys louisianae Roger, 1863 (Formicidae: Myrmicinae) from north-eastern Amazonia shed light on a difficult species complex
.
Zool Anz
.
2021
;
294
:
100
5
.
5.
Bolton
B
.
The ant tribe Dacetini
.
Mem Am Entomol Inst
.
2000
;
65
:
1
1028
.
6.
Bolton B
.
An online catalog of the ants of the world
. Available at: http://antcat.org. Accessed July 26, 2022.
7.
Cardoso
DC
,
Cristiano
MP
.
Karyotype diversity, mode, and tempo of the chromosomal evolution of Attina (Formicidae: Myrmicinae: Attini): is there an upper limit to chromosome number
.
Insects
.
2021
;
12
(
12
):
1084
.
8.
Gokhman
VE
.
Implication of chromosomal analysis for the taxonomy of parasitic wasps (Hymenoptera)
.
Entomol Rev
.
2006
;
86
(
1
):
1
10
.
9.
Green
CA
,
Baimai
V
,
Harrison
BA
,
Andre
RG
.
Cytogenetic evidence for a complex of species within the taxon Anopheles maculatus (Diptera: Culicidae)
.
Biol J Linn Soc Lond
.
1985
;
24
(
4
):
321
8
.
10.
Imai
HT
,
Taylor
RW
,
Crosland
MW
,
Crozier
RH
.
Modes of spontaneous chromosomal mutation and karyotype evolution in ants with reference to the minimum interaction hypothesis
.
Jpn J Genet
.
1988
;
63
(
2
):
159
85
.
11.
Imai
HT
,
Taylor
RW
,
Crozier
RH
.
Experimental bases for the minimum interaction theory. I. Chromosome evolution in ants of the Myrmecia pilosula species complex (Hymenoptera: Formicidae: Myrmeciinae)
.
Jpn J Genet
.
1994
;
69
:
137
82
.
12.
Kempf
WW
.
A revision of the neotropical ants of the Cyphomyrmex Mayr, part I: group of strigatus (Hym. Formicidae)
.
Studia Entomol
.
1964
;
7
:
1
44
.
13.
Kempf
WW
.
Revision of the neotropical ants of the genus Cyphomyrmex Mayr. Part II. Group of rimosus (spinola) (Hym: Formicidae)
.
Stud Entomol
.
1966
;
8
:
161
200
.
14.
König
C
,
Paschke
S
,
Pollmann
M
,
Reinisch
R
,
Gantert
C
,
Weber
J
,
.
Molecular and cytogenetic differentiation within the Lariophagus distinguendus (Förster, 1841) species complex (Hymenoptera, Pteromalidae)
.
Comp Cytogenet
.
2019
;
13
(
2
):
133
45
.
15.
Levan
A
,
Fredga
K
,
Sandberg
AA
.
Nomenclature for centromeric position on chromosomes
.
Hereditas
.
2009
;
52
(
2
):
201
20
.
16.
Marchioro
P
,
Campos
LAO
,
Lopes
DM
.
First record of a B chromosome in Polybia fastidiosuscula Saussure (Vespidae) and investigation of chromatin composition through microsatellite mapping
.
Cytogenet Genome Res
.
2020
;
160
(
11-12
):
711
8
.
17.
Mariano
CSF
,
Pompolo
SdG
,
Silva
JG
,
Delabie
JHC
.
Contribution of cytogenetics to the debate on the paraphyly of Pachycondyla spp. (Hymenoptera, Formicidae, Ponerinae)
.
Psyche: A Journal of Entomology
.
2012
;
2012
:
1
9
.
18.
Mariano
CSF
,
Barros
LAC
,
Velasco
YM
,
Guimarães
IN
,
Pompolo
SG
,
Delabie
JHC
.
Citogenética de hormigas de la región neotropical
. In:
Fernández
F
,
Guerrero
R
,
Delsinne
T
, editors.
Hormigas de Colombia
.
Bogotá
:
Universidad Nacional de Colombia
;
2019
. p.
131
57
.
19.
Mariano
CSF
,
Santos
IS
,
Groc
S
,
Leroy
C
,
Malé
PJ
,
Ruiz-González
MX
,
.
The karyotypes of Gigantiops destructor (Fabricius) and other ants from French Guiana (Formicidae)
.
Ann Soc Entomol Fr
.
2011
;
47
(
1–2
):
140
146
.
20.
Mehdiabadi
NJ
,
Schultz
TR
.
Natural history and phylogeny of the fungus-farming ants (Hymenoptera: Formicidae: Myrmicinae: Attini)
.
Myrmecol News
.
2010
;
13
:
37
55
.
21.
Menezes
RST
,
Cabral‐de‐Mello
DC
,
Milani
D
,
Bardella
VB
,
Almeida
EAB
.
The relevance of chromosome fissions for major ribosomal DNA dispersion in hymenopteran insects
.
J Evol Biol
.
2021
;
34
(
9
):
1466
76
.
22.
Micolino
R
,
Cristiano
MP
,
Cardoso
DC
.
Population-based cytogenetic banding analysis and phylogenetic relationships of the neotropical fungus-farming ant Trachymyrmex holmgreni Wheeler
.
Cytogenet Genome Res
.
2019
b;
159
(
3
):
151
61
.
23.
Micolino
R
,
Cristiano
MP
,
Travenzoli
NM
,
Lopes
DM
,
Cardoso
DC
.
Chromosomal dynamics in space and time: evolutionary history of Mycetophylax ants across past climatic changes in the Brazilian Atlantic coast
.
Sci Rep
.
2019a
;
9
(
1
):
18800
13
.
24.
Micolino
R
,
Baldez
BCL
,
Sánchez-Restrepo
AF
,
Calcaterra
L
,
Cristiano
MP
,
Cardoso
DC
.
Karyotype structure and cytogenetic markers of Amoimyrmex bruchi and Amoimyrmex silvestrii: contribution to understanding leaf-cutting ant relationships
.
Genome
.
2022
;
65
(
1
):
43
51
.
25.
Murakami
T
,
Fujiwara
A
,
Yoshida
MC
.
Cytogenetics of ten ant species of the tribe Attini (Hymenoptera, Formicidae) in Barro Colorado Island, Panama
.
Chromosome Sci
.
1998
;
2
:
135
9
.
26.
Pereira
JOP
.
Diversidade genética da abelha sem ferrão Melipona quinquefasciata baseada no sequenciamento das regiões ITS1 parcial e 18S do DNA ribossômico nuclear
.
Universidade Federal do Ceará
;
2006
.
27.
Pinkel
D
,
Straume
T
,
Gray
JW
.
Cytogenetic analysis using quantitative, high-sensitivity, fluorescence hybridization
.
Proc Natl Acad Sci U S A
.
1986
;
83
(
9
):
2934
8
.
28.
Schlick-Steiner
BC
,
Steiner
FM
,
Seifert
B
,
Stauffer
C
,
Christian
E
,
Crozier
RH
.
Integrative Taxonomy: a multisource approach to exploring biodiversity
.
Annu Rev Entomol
.
2010
;
55
:
421
38
.
29.
Schneider
CA
,
Rasband
WS
,
Eliceiri
KW
.
NIH Image to ImageJ: 25 years of image analysis
.
Nat Methods
.
2012
;
9
(
7
):
671
5
.
30.
Schweizer
D
.
Simultaneous fluorescent staining of R bands and specific heterochromatic regions (DA/DAPI-bands) in human chromosomes
.
Cytogenet Cell Genet
.
1980
;
27
(
2-3
):
190
3
.
31.
Snelling
RR
,
Longino
JT
.
Revisionary notes on the fungus-growing ants of the genus Cyphomyrmex, rimosus-group (Hymenoptera: Formicidae: Attini)
. In:
Quintero
D
,
Aiello
A
, editors.
Insects of Panama and Mesoamerica: Selected Studies
.
Oxford
:
Oxford University Press
;
1992
. p.
479
94
.
32.
Sosa-Calvo
J
,
Jesovnik
A
,
Okonski
E
,
Schultz
TR
.
Locating, collecting, and maintaining colonies of fungus-farming ants (Hymenoptera: Myrmicinae: Attini)
.
Sociobiology
.
2015
;
62
(
2
):
300
20
.
33.
Sosa-Calvo
J
,
Ješovnik
A
,
Vasconcelos
HL
,
Bacci
M
Jr
,
Schultz
TR
.
Rediscovery of the enigmatic fungus-farming ant "Mycetosoritis" asper Mayr (Hymenoptera: Formicidae): implications for taxonomy, phylogeny, and the evolution of agriculture in ants
.
PLoS One
.
2017
;
12
(
5
):
e0176498
.
34.
Sumner
AT
.
A simple technique for demonstrating centromeric heterochromatin
.
Exp Cell Res
.
1972
;
75
(
1
):
304
6
.
35.
Teixeira
GA
,
Barros
LAC
,
de Aguiar
HJAC
,
Lopes
DM
.
Distribution of GC-rich heterochromatin and ribosomal genes in three fungus-farming ants (Myrmicinae, Attini, Attina): insights on chromosomal evolution
.
Comp Cytogenet
.
2021a
;
15
(
4
):
413
28
.
36.
Teixeira
GA
,
de Aguiar
HJAC
,
Petitclerc
F
,
Orivel
J
,
Lopes
DM
,
Barros
LAC
.
Evolutionary insights into the genomic organization of major ribosomal DNA in ant chromosomes
.
Insect Mol Biol
.
2021b
;
30
(
3
):
340
54
.
37.
Teixeira
GA
,
Barros
LAC
,
de Aguiar
HJAC
,
Lopes
DM
.
Multiple heterochromatin diversification events in the genome of fungus-farming ants: insights from repetitive sequences
.
Chromosoma
.
2022
;
131
(
1-2
):
59
75
.
38.
Travenzoli
NM
,
Lima
BA
,
Cardoso
DC
,
Dergam
JA
,
Fernandes-Salomão
TM
,
Lopes
DM
.
Cytogenetic analysis and chromosomal mapping of repetitive DNA in Melipona species (Hymenoptera, Meliponini)
.
Cytogenet Genome Res
.
2019
;
158
(
4
):
213
24
.
39.
Weber
NA
.
Fungus-growing ants
.
Science
.
1966
;
153
(
3736
):
587
604
.
You do not currently have access to this content.